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Butler Performance IAII Aluminum Block, STD Deck 

Aluminum, 2SR Spriniam, spec AA356, heat treated to T6
Ductile Iron Sleeve Material
4.170 to 4.350" Bore depending on sleeves
10.240" Deck Height
4 Billet Steel splayed Main Caps, registered and dowel pinned
3" Crank
50 or 55mm Cam Tunnel
Any OE or Aftermarket 3" crank and Pontiac rear main seal
Availability: Shipping is delivered to a business address. Additional charges for residential or lift gate may apply
Pricing: $4,795.00

Customize Your Item

- Choose Cam Tunnel Size -
 * required
- Choose Lifter Bore Bushings -
 * required
- Choose IAII add-on Items -
 * required


$299 handling fee covers delivery to anywhere in Continental US


These blocks can be used in almost any application from street use (fully water jacketed) to all out racing engines.
AP/BUTLER PERFORMANCE Aluminum Pontiac Block-Std Deck

All IAII Blocks include main caps and main studs

**Price Does Not Include machining/bearings for 50MM or 55MM cam

Cast Block Features
Standard with every IA II block**
Siamese Cylinders: 4.170" Bore but can be bored up to 4.350"
All steel registered main caps: With splayed four bolt pattern on the three center mains which adds rigidity
Block cast: Allows clearance for 4.750 stroke crank.
Main webs: Strengthened to maximum width possible.
Cam tunnels: Reinforced.
Wider pan rails: Provides better oil pan gasket sealing and gasket retention.
Thicker deck surfaces: Provides added strength and aids in cylinder head sealing
Solid lifter galley: With drilled oil returns that prevents lifter bore breakage and adds strength
Improved oiling: Front main oil feed, which adds longevity and helps prevent front main bearing "starvation".
Bottom of the block: Is solid to the bend, above the pan rail, for added strength
IA II Blocks have Redesigned Block Cooling Passages: Improves cooling to all cylinders.
Provisions for external cooling: 1/2" NPT holes provided at the rear of the block. Gives you the option to dry deck the block.
Dual bell housing bolt patterns: For both Pontiac and "corporate" housings.
Lifter bores are deeper to allow the use of standard type "corporate" lifters.
Bottoms of cylinders: Are notched to clear strokes up to 4.75". A 5.0" stroke is possible with some grinding.
Head bolt bosses: Are tied to cylinder walls and the exterior block walls are thicker for added strength.
Oil filter passages are threaded for easy remote filter mounting. Oil pump passages have corner plugs at 90-degree turns to reduce flow restriction. (Plugs are included with kit.)
The IA II Block uses standard Pontiac 5 bolt Motor mount pattern.
Standard deck height: IA II Blocks are available with 3"
Threaded freeze plug holes: For safety and wall rigidity. This lessens the chance of the engine blowing out a freeze plug.

* Drilling is required to match your heads water holes. Estimated drilling time; 10 minutes.
There is no longer a material alloy surcharge!
Our IA II blocks are machined by one of the best aftermarket engine machine shops in the country. All blocks are checked out on a CNC coordinate measuring machine with-in process probing during manufacturing. We pressure test and sonic check every block. IA II Blocks come with a full warranty for material and workmanship.
ALL Blocks are shipped DRY DECK*

Optional Finishing Kit (Plugs/Dowels Pins) for IA II Block
2- 1'' Flush Fit Pipe Plugs(SPE-1FP)
5- 1/2'' Pipe Plugs (568)
4- 3/8'' Pipe Plugs (554)
1- 3/8" Pipe Plug -Drilled (475)
1- 1/8'' Pipe Plugs (638)
1- 15/16'' Press-in Plug (EPC-39)
1- Cam Plug (EPC-112/STD) *OPTIONAL PIO-EPC92/50MM cam*
2- Drain Spigots
4- Dowels for Deck(MSC-06025068)
2-Bellhousing Dowel Pins(TCI-930055)
1-ALL-AP-OPS Front Oil Pan Spacer


  • AllPontiac
  • Shipping is delivered to a business address. Additional charges for residential or lift gate may apply
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Customer Reviews

Comment Total Reviews (1)

IA 2 Aluminum Block JBP prepped
  • Currently 5/5 Stars

Reviewed by:

Product ownership: A year or longer

Purchased from: Butler Performance Inc.

I purchased this block & crank kit from JBP 2 years back and have it installed in a 1970 all steel street/strip GTO @4,100 lbs with driver. The engine is 505CID, EFI, & D1X Procharger to 13psi @ 6500rpm. The block prep by JBP was flawless and all of my existing accessories fit, with some adjustment to the drivers side middle freeze plug to clear the inner header tube on Hooker competition plus headers. I have been racing the 1/4 mile with 10.00 @135mph for 2 years while driving it to the track & back home and 100's of miles to shows and meets. There have been 0 issues. I highly recommend this block for longevity & performance for racing or street.

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