Bore, Stroke and Compression — 400 Pistons for Pontiac V8s
400 Pistons decide the two numbers that matter most on a Pontiac 400 build: your finished bore and your compression ratio. A standard 4.120" bore refresh and a 4.500" stroke pump gas stroker both start here, and the piston you pick also sets your ring package, your pin size and how much compression height the rod and stroke leave you to work with.
Butler stocks Keith Black hypereutectic and Icon forged pistons from standard through .060" over, DSS 2618 forged pistons for 3.750" through 4.500" strokes, and Butler/Ross forged pistons on a Ross Pontiac forging made exclusively for Butler, including Quick Ship flat tops and dish tops CNC milled in house.
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.250" Str., 4.150" Bore, -18cc Dish Top, Set/8, DSS-K3-6135-4150CNew
DSS 3-FX Series Forged Pistons — Set of 8
-18cc Dish Top
4.150" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Ext...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-18cc Dish Top
4.150" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6135-4150C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.250" Str., 4.150" Bore, -7cc Flat Top, Set/8, DSS-K3-6130-4150CNew
DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.150" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extr...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.150" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6130-4150C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.250" Str., 4.160" Bore, -18cc Dish Top, Set/8, DSS-K3-6135-4160CNew
DSS 3-FX Series Forged Pistons — Set of 8
-18cc Dish Top
4.160" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Ext...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-18cc Dish Top
4.160" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6135-4160C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.250" Str., 4.160" Bore, -7cc Flat Top, Set/8, DSS-K3-6130-4160CNew
DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.160" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extr...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.160" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6130-4160C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.250" Str., 4.180" Bore, -18cc Dish Top, Set/8, DSS-K3-6135-4180CNew
DSS 3-FX Series Forged Pistons — Set of 8
-18cc Dish Top
4.180" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Ext...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-18cc Dish Top
4.180" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6135-4180C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.250" Str., 4.180" Bore, -7cc Flat Top, Set/8, DSS-K3-6130-4180CNew
DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.180" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extr...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.180" Bore / 4.250" Stroke
1.285" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6130-4180C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.500" Str., 4.150" Bore, -24cc Dish Top, Set/8, DSS-K3-6157-4150CNew
DSS 3-FX Series Forged Pistons — Set of 8
-24cc Dish Top
4.150" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extr...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-24cc Dish Top
4.150" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6157-4150C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.500" Str., 4.150" Bore, -7cc Flat Top, Set/8, DSS-K3-6150-4150CNew
DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.150" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extre...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.150" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6150-4150C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.500" Str., 4.180" Bore, -24cc Dish Top, Set/8, DSS-K3-6157-4180CNew
DSS 3-FX Series Forged Pistons — Set of 8
-24cc Dish Top
4.180" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extr...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-24cc Dish Top
4.180" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6157-4180C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS 3-FX Forged Piston and Ring Kit, Pontiac 455, 4.500" Str., 4.180" Bore, -7cc Flat Top, Set/8, DSS-K3-6150-4180CNew
DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.180" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with Extre...
Description: DSS 3-FX Series Forged Pistons — Set of 8
-7cc Flat Top
4.180" Bore / 4.500" Stroke
1.16" Compression Height
0.99" Pins Included
1.2 / 1.2 / 3.0mm DSS Ring Set Included
2618 with...More Details »
Item #: DSS-K3-6150-4180C
Condition: New
Ships in 7-10 Business Days
Price: $1,259.95
DSS Custom Piston Set, Up to 4.200 Bore, Any Stroke, Flat or Dish, SetNew
Fully Custom DSS Pistons
Made with 2618 - T6 forging
Choose Dish or Flat Top
Any Stroke and up to 4.200 Bore
Choose rings, pins, and more
Enter specs and details to help us customize it
Our experts...
Description: Fully Custom DSS Pistons
Made with 2618 - T6 forging
Choose Dish or Flat Top
Any Stroke and up to 4.200 Bore
Choose rings, pins, and more
Enter specs and details to help us customize it
Our experts...More Details »
-14cc Dish Top Pistons
4.150", 4.160", or 4.180 Bore
1.585 CH
.980" Pins Included
6.625" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Description: -14cc Dish Top Pistons
4.150", 4.160", or 4.180 Bore
1.585 CH
.980" Pins Included
6.625" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
-18cc Dish Top Pistons
4.150", 4.160", or 4.180 Bore
1.480 CH
.980" Pins Included
6.625" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Description: -18cc Dish Top Pistons
4.150", 4.160", or 4.180 Bore
1.480 CH
.980" Pins Included
6.625" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
-24cc Dish Top Pistons
4.150", 4.160", or 4.180 Bore
1.160 CH
.990" Pins Included
6.800" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Description: -24cc Dish Top Pistons
4.150", 4.160", or 4.180 Bore
1.160 CH
.990" Pins Included
6.800" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Item #: DSS-2-6153-400
Condition: New
Ships in 7-10 Business Days
Price: $799.95
DSS Forged -7cc Flat Top Pistons, 400/428, 4.000" Str,New
Forged Flat Top Pistons
-7cc Valve Pocket
4.150", 4.160", or 4.180 Bore
1.585 CH
.980" Pins Included
6.625" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Description: Forged Flat Top Pistons
-7cc Valve Pocket
4.150", 4.160", or 4.180 Bore
1.585 CH
.980" Pins Included
6.625" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Item #: DSS-2-6112-428
Condition: New
Price: $799.95
DSS Forged -7cc Flat Top Pistons, 400/428, 4.500" Str,New
Forged Flat Top Pistons
-7cc Valve Pocket
4.150", 4.160", or 4.180 Bore
1.160 CH
.990" Pins Included
6.800" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Description: Forged Flat Top Pistons
-7cc Valve Pocket
4.150", 4.160", or 4.180 Bore
1.160 CH
.990" Pins Included
6.800" Rod Length
1.2 1.2 3.0mm Rings Required
Fits late model and Edelbrock Cylinder Heads
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400 (or 389 +.058")
-10.8cc Flat Top
4.180" Bore (+.060")
3.750" Stroke
1.714" Compression Height
.980" Pins Included
5/64, 5/64,...More Details »
Item #: UEM-IC-9946-KTD-060-8
Condition: New
Ships in 7-10 Business Days
Price: $770.63
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.120" Bore (Std), -14cc Dish, Set/8, UEM-IC-891-KTD-STD-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.120" Bore (Standard)
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.120" Bore (Standard)
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-891-KTD-STD-8
Condition: New
Ships in 7-10 Business Days
Price: $878.08
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.150" Bore (+.030"), -14cc Dish, Set/8, UEM-IC-891-KTD-030-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.150" Bore (+.030")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.150" Bore (+.030")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-891-KTD-030-8
Condition: New
Ships in 7-10 Business Days
Price: $878.08
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.150" Bore (+.030"), -4.5cc Flat Top, Set/8, UEM-IC-890-KTD-030-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-4.5cc Flat Top
4.150" Bore (+.030")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-4.5cc Flat Top
4.150" Bore (+.030")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-890-KTD-030-8
Condition: New
Ships in 7-10 Business Days
Price: $860.52
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.160" Bore (+.040"), -14cc Dish, Set/8, UEM-IC-891-KTD-040-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.160" Bore (+.040")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.160" Bore (+.040")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-891-KTD-040-8
Condition: New
Ships in 7-10 Business Days
Price: $878.08
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.160" Bore (+.040"), -4.5cc Flat Top, Set/8, UEM-IC-890-KTD-040-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-4.5cc Flat Top
4.160" Bore (+.040")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-4.5cc Flat Top
4.160" Bore (+.040")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-890-KTD-040-8
Condition: New
Ships in 7-10 Business Days
Price: $860.52
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.180" Bore (+.060"), -14cc Dish, Set/8, UEM-IC-891-KTD-060-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.180" Bore (+.060")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-14cc Dish
4.180" Bore (+.060")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-891-KTD-060-8
Condition: New
Ships in 7-10 Business Days
Price: $878.08
Icon Forged Piston and Ring Kit, Pontiac 400, 3.750" Str., 4.180" Bore (+.060"), -4.5cc Flat Top, Set/8, UEM-IC-890-KTD-060-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-4.5cc Flat Top
4.180" Bore (+.060")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 400
-4.5cc Flat Top
4.180" Bore (+.060")
3.750" Stroke
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-890-KTD-060-8
Condition: New
Ships in 7-10 Business Days
Price: $860.52
Icon Forged Piston and Ring Kit, Pontiac 428, 4.000" Str., 4.150" Bore (+.030"), -10cc Dish, Set/8, UEM-IC-892-KTD-030-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 428
-10cc Dish
4.150" Bore (+.030")
4.000" Stroke
1.595" Compression Height
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 428
-10cc Dish
4.150" Bore (+.030")
4.000" Stroke
1.595" Compression Height
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-892-KTD-030-8
Condition: New
Ships in 7-10 Business Days
Price: $920.53
Icon Forged Piston and Ring Kit, Pontiac 428, 4.000" Str., 4.160" Bore (+.040"), -10cc Dish, Set/8, UEM-IC-892-KTD-040-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 428
-10cc Dish
4.160" Bore (+.040")
4.000" Stroke
1.595" Compression Height
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 428
-10cc Dish
4.160" Bore (+.040")
4.000" Stroke
1.595" Compression Height
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Item #: UEM-IC-892-KTD-040-8
Condition: New
Ships in 7-10 Business Days
Price: $920.53
Icon Forged Piston and Ring Kit, Pontiac 428, 4.000" Str., 4.180" Bore (+.060"), -10cc Dish, Set/8, UEM-IC-892-KTD-060-8New
Icon Forged Pistons with Rings — Set of 8
Pontiac 428
-10cc Dish
4.180" Bore (+.060")
4.000" Stroke
1.595" Compression Height
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Description: Icon Forged Pistons with Rings — Set of 8
Pontiac 428
-10cc Dish
4.180" Bore (+.060")
4.000" Stroke
1.595" Compression Height
.980" Pins Included
1/16, 1/16, 3/16 Ring Set Included
Every piston on this page is sold to a finished bore, not to a guess. Measure what the block actually is, or tell your machinist what you plan to order, before anything gets bought.
Standard 4.120"
The stock Pontiac 400 bore. Keith Black and Icon both list a standard bore set, so a block that cleans up without an overbore does not force you into oversize pistons.
.030" over (4.150")
The most common rebuild size and the bore Butler stocks most heavily across Keith Black, Icon, DSS and Ross Quick Ship.
.040" over (4.160") and .060" over (4.180")
Available in the Keith Black and Icon families as complete sets of eight, plus DSS forged sets listed for 4.150", 4.160" and 4.180".
4.155", 4.181" and 4.200"
Butler/Ross Quick Ship and custom Ross pistons cover the in-between and larger sizes that a sonic-tested block will support.
2. Hypereutectic cast or forged
Both paths are legitimate on a 400. The question is what the engine is going to be asked to do.
Keith Black hypereutectic
Hypereutectic 390 alloy with 16 percent silicon, diamond-machined skirt, spiral lock rings, press-fit or bushed wrist pins. Butler lists them in a -6cc flat top and a -17cc dish, both in .030", .040" and .060" over. They come with pin locks, so they work with bushed or press-fit rods.
Icon forged
Forged 2618 aluminum in a -4.5cc flat top and a -14cc D-shaped dish, sold as matched sets of eight in standard, .030", .040" and .060" over. Press-fit or floating on a .980" pin, 1/16", 1/16", 3/16" ring grooves.
DSS forged
2618 alloy with the patented X Groove skirt, drilled forced pin oiling and deep CNC valve reliefs, offered in flat top and dish for 3.750", 4.000", 4.210", 4.250" and 4.500" strokes.
Butler/Ross forged
2618-T61 on a Pontiac-specific forging Ross developed for Butler, in a strut-style design that runs tighter piston-to-wall clearance than a generic forging.
3. Dish, flat top and the compression you can actually run
Butler's own guidance is worth repeating: no more than 9.5:1 on cast iron heads and no more than 10.5:1 on aluminum heads for pump gas. Pick the dish that gets you there with the chamber you already own.
Flat tops
Icon's -4.5cc flat top lands near 10.9:1 with a 71cc chamber, 9.3:1 at 87cc and 8.6:1 at 96cc on a stock-stroke 400. That is the classic cast-iron-head combination when the chamber is large enough.
Dish tops
Icon's -14cc dish runs roughly 9.9:1 at 71cc, 8.6:1 at 87cc and 8.0:1 at 96cc. Keith Black's -17cc dish is the deepest stock-stroke dish Butler lists for a 400.
Butler-milled dishes
The Ross Quick Ship dish pistons arrive at Butler as a thick flat top and get finished on a five-axis CNC mill to a dish between -16cc and -42cc, so the compression ratio is cut to your chamber instead of the other way around.
Fully custom
Ross and DSS custom sets let you specify bore, stroke, dome, dish or flat top. Tell Butler the heads and the compression ratio you want and the piston gets designed to hit it.
4. Compression height has to match the stroke and rod
This is where most 400 piston orders go wrong. Longer stroke means the piston has to get shorter, and the rod length has to be chosen at the same time.
3.750" stock stroke
DSS lists 1.710" compression height on a 6.625" rod; Icon lists 1.720" on a 6.630" rod with a .980" pin.
4.000" stroke
1.585" compression height, still on the 6.625" rod in the DSS listing.
4.210" stroke
1.480" compression height.
4.250" stroke
1.285" on a 6.800" rod with a .990" pin in the DSS listing, or 1.295" on the Butler/Ross Quick Ship pistons.
4.500" stroke
1.160" compression height. At this point the piston is short, the pin is high in the skirt and the rest of the combination needs to be built around it.
5. Head style and valve angle
A 400 piston has to clear the valves in the heads you are running, and Butler's listings call out which heads each piston was cut for.
14 degree heads, 1967 and later
The Keith Black -6cc flat top is listed specifically for these.
14 and 20 degree heads
The Keith Black -17cc dish covers both.
OE or Edelbrock style heads
Icon's note on both the flat top and the dish sets. DSS dish pistons for the 400 are listed as fitting late model and Edelbrock cylinder heads.
Dual valve pocket
Where a DSS piston is listed with a dual pocket, it is cut to clear both the early and the late valve angle, which matters if the heads are not decided yet.
6. What comes with the piston and what you still need
Rings
Some sets include a ring package and some do not. The Ross Quick Ship flat tops list pins and rings as not included; the dish versions include pins but not rings. Match the ring set to the finished bore, not to the nominal overbore.
Pins and locks
Icon and DSS sets include the pin. Keith Black pistons ship with pin locks so they can be run bushed or press-fit.
Rod clearance
Butler flags it on nearly every forged listing. Stock cast rods may need the small end narrowed and the balance pad removed to clear the inside of the pistons.
Early blocks and power adders
Ross builds an oil ring support version of the -8cc flat top specifically for early 400 blocks with deep notches, and for nitrous and boost applications where the oil ring groove needs the extra support.
Lead time
Custom pistons are not returnable, and a fully custom dish takes real time to produce. Quick Ship sets exist for exactly that reason.
If you know your bore, your stroke, your rod length and your chamber volume, a Butler tech can put a 400 piston in front of you in one phone call. If you only know two of the four, call before you order, because the piston is the part that locks the other three in place.
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.