Butler Performance IAII Cast Iron Block, STD Deck, Custom Bore, ALL-APSJB-Custom-Bore

Std Deck IA II After Market Block - 3" Mains

All IAII Blocks include main caps and main studs

Cast Block Features
Standard with every IA II block**
Siamese Cylinders: 4.145 to 4.400" bores with min. of .200 wall thickness @ 4.400 bore. This provides outstanding cylinder wall rigidity. No other block has this
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 rear of 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.
Threaded freeze plug holes: For safety and wall rigidity. (Freeze plugs are provided with block.) 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 buy one of the best aftermarket engine machine shops in the country. All blocks are check 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*