The 389 is the engine that built Pontiac's reputation, and it is the one displacement where the piston question has an extra step: the 389 came in an early and a late style, and the piston is not the same. Getting that right before you order is the whole job.
Butler stocks Butler Ross Quick Ship forged flat tops and dish tops for the 389 in 4.092" and 4.122" bores at both 3.75" and 4.250" stroke, plus Keith Black hypereutectic cast sets and fully custom Ross and DSS pistons for early or late blocks.
Butler Ross Quick Ship -8cc Flat Top Forged Pistons, 3.75" Str., 4.092 Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
3.75 Stroke
1.720 Ch
4.092 Bore
Dual Valve Pocket (late 14 and early 22 degree heads)
Includes Pins
1/16 1/16 3/16 Ring Size
Rings not included
Stock rods...
Description: Quick Ship from Butler Ross Racing Pistons
3.75 Stroke
1.720 Ch
4.092 Bore
Dual Valve Pocket (late 14 and early 22 degree heads)
Includes Pins
1/16 1/16 3/16 Ring Size
Rings not included
Stock rods...More Details »
Item #: ROS-BU3754092-8
Condition: New
Price: $799.95
Butler Ross Quick Ship -8cc Flat Top Forged Pistons, 3.75" Str., 4.122 Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
3.75 Stroke
1.720 Ch
4.122 Bore
Dual Valve Pocket (late 14 and early 22 degree heads)
1/16 1/16 3/16 Ring Size
Includes Pins
Rings not included
Stock rods...
Description: Quick Ship from Butler Ross Racing Pistons
3.75 Stroke
1.720 Ch
4.122 Bore
Dual Valve Pocket (late 14 and early 22 degree heads)
1/16 1/16 3/16 Ring Size
Includes Pins
Rings not included
Stock rods...More Details »
Item #: ROS-BU3754122-8
Condition: New
Price: $799.95
Butler Ross Quick Ship -8cc Flat Top Forged Pistons, 4.250" Str., 4.092 Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
4.250 Stroke
1.295 Ch
4.092 Bore
Dual Valve Pocket (late 14 and early 22 degree heads)
Includes Pins
Rings not included
Stock rods small end must be narro...
Description: Quick Ship from Butler Ross Racing Pistons
4.250 Stroke
1.295 Ch
4.092 Bore
Dual Valve Pocket (late 14 and early 22 degree heads)
Includes Pins
Rings not included
Stock rods small end must be narrowed for use with these pistons
Item #: ROS-BU4254092-8
Condition: New
Price: $1,117.95
Butler Ross Quick Ship -8cc Flat Top Forged Pistons, 4.250" Str., 4.122 Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
4.250 Stroke
1.295 Ch
4.122 Bore
1/16 1/16 3/16 Ring Size
Includes Pins
Rings not included
Stock rods small end must be narrowed for use with these pistons
Description: Quick Ship from Butler Ross Racing Pistons
4.250 Stroke
1.295 Ch
4.122 Bore
1/16 1/16 3/16 Ring Size
Includes Pins
Rings not included
Stock rods small end must be narrowed for use with these pistons
Item #: ROS-BU4254122-8
Condition: New
Price: $749.95
Butler Ross Quick Ship 16 to 42cc Dish Top Forged Pistons, 3.750" Str., 4.092" Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
3.750 Stroke
1.720Ch
4.092 Bore
14 and 22 Degree Heads
1/16 1/16 3/16 Ring Size
Pins Included
Rings not included
Stock...
Description: Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
3.750 Stroke
1.720Ch
4.092 Bore
14 and 22 Degree Heads
1/16 1/16 3/16 Ring Size
Pins Included
Rings not included
Stock...More Details »
Item #: ROS-BU3754092-DS-8
Condition: New
Price: $999.95
Butler Ross Quick Ship 16 to 42cc Dish Top Forged Pistons, 3.750" Str., 4.122" Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
3.750 Stroke
1.720Ch
4.122 Bore
1/16 1/16 3/16 Ring Size
Pins Included
Rings not included
Stock rods small end must be...
Description: Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
3.750 Stroke
1.720Ch
4.122 Bore
1/16 1/16 3/16 Ring Size
Pins Included
Rings not included
Stock rods small end must be narrowed for use with these pistons
Item #: ROS-BU3754122-DS-8
Condition: New
Price: $999.95
Butler Ross Quick Ship 16 to 42cc Dish Top Forged Pistons, 4.250" Str., 4.092" Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
4.250 Stroke
1.295Ch
4.092 Bore
Late 14 and early 22 degree heads
1/16 1/16 3/16 Ring Size
Pins Included
Rings not inc...
Description: Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
4.250 Stroke
1.295Ch
4.092 Bore
Late 14 and early 22 degree heads
1/16 1/16 3/16 Ring Size
Pins Included
Rings not...More Details »
Item #: ROS-BU4254092-DS-8
Condition: New
Price: $949.95
Butler Ross Quick Ship 16 to 42cc Dish Top Forged Pistons, 4.250" Str., 4.122" Bore, Set/8New
Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
4.250 Stroke
1.295Ch
4.122 Bore
1/16 1/16 3/16 Ring Size
Pins Included
Rings not included
Stock rods small end must be...
Description: Quick Ship from Butler Ross Racing Pistons
Custom Dish CC CNC Milled at Butler
4.250 Stroke
1.295Ch
4.122 Bore
1/16 1/16 3/16 Ring Size
Pins Included
Rings not included
Stock rods small end must be narrowed for use with these pistons
Item #: ROS-BU4254122-DS-8
Condition: New
Price: $949.95
Diamond Custom Piston Set, Any Bore, Any Stroke, Flat, Dish, or Dome, SetNew
Fully Custom Diamond Pistons
Made with 2618 - T6 forging
Choose Dish, Dome, or Flat Top
Any Stroke or Bore
Choose rings, pins, and more
Enter specs and details to help us customize it
Our exp...
Description: Fully Custom Diamond Pistons
Made with 2618 - T6 forging
Choose Dish, Dome, or Flat Top
Any Stroke or Bore
Choose rings, pins, and more
Enter specs and details to help us customize it
Our...More Details »
Item #: DIA-CUSTOM
Condition: New
Ships in 14-16 weeks
Price: $1,429.00
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.080" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4080New
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4080
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.080" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4080New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4080
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.080" Bore, -7cc Flat Top, Set/8, DSS-K1-6102-4080New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6102-4080
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.100" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4100New
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4100
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.100" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4100New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4100
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.100" Bore, -7cc Flat Top, Set/8, DSS-K1-6102-4100New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6102-4100
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.120" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4120New
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4120
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.120" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4120New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4120
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.120" Bore, -7cc Flat Top, Set/8, DSS-K1-6102-4120New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6102-4120
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.125" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4125New
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4125
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.125" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4125New
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4125
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.190" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4190New
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.190" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.190" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4190
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.080" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4080CNew
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4080C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.080" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4080CNew
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4080C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.100" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4100CNew
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4100C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.100" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4100CNew
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.100" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4100C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.120" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4120CNew
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4120C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.120" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4120CNew
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.120" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4120C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.125" Bore, -14cc Dish Top, Set/8, DSS-K1-6104-4125CNew
DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6104-4125C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 1-FX Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.125" Bore, -7cc Flat Top, Set/8, DSS-K1-6100-4125CNew
DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging &m...
Description: DSS 1-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.125" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
4032 forging...More Details »
Item #: DSS-K1-6100-4125C
Condition: New
Ships in 7-10 Business Days
Price: $1,029.95
DSS 2-FX Forged Piston and Ring Kit, Pontiac 389, 3.750" Str., 4.080" Bore, -14cc Dish Top, Set/8, DSS-K2-6104-4080New
DSS 2-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 forging &...
Description: DSS 2-FX Series Forged Pistons — Set of 8
-14cc Dish Top
4.080" Bore / 3.750" Stroke
1.71" Compression Height
0.98" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 forging...More Details »
Butler's 389 custom pistons are catalogued as "Early or Late 389" for a reason, and the off-the-shelf sets carry head compatibility notes that mean exactly what they say.
Early 389
The DSS forged set catalogued for the early style 389 is listed as fitting 1964-66 22-degree cylinder heads only. That note appears twice on the product, which tells you how often it gets missed.
Late 389
DSS catalogues a separate late-style piston. Same stroke, different part.
Keith Black
The hypereutectic flat top Butler stocks for the 389 is listed for the early style block at the 3.750" stroke.
If you are not sure
Have the block casting and the cylinder head in front of you before you order. This is not a piston you can swap after the fact.
2. Bore sizes
The 389 bore list is tighter than the 400 or 455, and the Butler Ross sets are cut to specific finished sizes rather than nominal overbore steps.
4.092"
The smaller of the two Quick Ship bores, available in flat top and dish at both strokes.
4.122"
The larger Quick Ship bore, same crown options.
DSS bores
The DSS early-style forged piston is listed for 4.080" or 4.100" bore.
Keith Black
Catalogued in .030" and .060" over for the 389.
Measure after honing
Order the piston to what the block actually measures. Custom pistons are not returnable.
3. Cast or forged, and what the crown does
Two decisions that come as a pair on a 389, because most of these engines are either going back together stock or being turned into something considerably larger.
Keith Black hypereutectic
A high-silicon cast piston that runs tight and quiet and handles street and mild-performance use. The correct choice for a numbers-matching 389 that will spend its life on the street. Note that Keith Black specifies a much wider top ring end gap than a forged piston — .0065" per inch of bore for a street engine.
Ross forged
Butler's Quick Ship sets are 8cc flat tops and dish tops covering a 16 to 42cc dish range, which is how you land on a compression target against a known chamber volume.
DSS GSX forged
2618 alloy with the patented X Groove skirt, larger and deeper CNC valve reliefs for aggressive head and cam combinations, drilled forced wrist pin oiling, and diamond turned high-strength skirts. DSS quotes 9.50:1 against a 72cc chamber, 8.99:1 against 78cc and 8.47:1 against 85cc on the early-style dish piston.
Ring package
The DSS early-style 389 piston requires a 1/16", 1/16", 3/16" ring set. Order the rings to the piston.
4. Stock stroke or stroker
A 389 block takes a lot more stroke than it left the factory with, and the piston changes with it.
3.75" stroke
The factory 389 stroke, on a 6.625" rod. The DSS early-style piston is listed at 1.710" compression height with .980" pins for that combination.
4.250" stroke
Butler stocks Quick Ship flat top and dish sets at this stroke in both 389 bores. The compression height drops and the rod length grows — crank, rod and piston are one order.
Custom in between
Ross custom pistons for the 389 are catalogued at 3.75", 4.000" and 4.250" stroke for early or late blocks, and DSS builds custom 2618-T6 pistons for any stroke up to a 4.200" bore.
Four numbers get you to the right 389 piston: early or late block, finished bore, crank stroke and cylinder head chamber cc. Have those and the call takes a minute.
Not sure what your Pontiac needs?
Call our tech team at 866-762-7527. Tell us your engine, heads, car, and power goal, and we will put the parts together as one combination that works.