Engine & Components

IA II AllPontiac Aluminum Engine Block  
IA II Pontiac Engine Block (side)

IA II AllPontiac Aluminum Engine Block
Cylinder Bore: 4.245"
3" Main
Price: $4,495.00
Part Number: APSJBA
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  • Our IA II blocks are machined by one of
    the best aftermarket engine machine shops in the country.
  • All blocks are checked on a CNC coordinate measuring machine with-in process probing during manufacturing.
  • Every block is pressure tested and
    comes with a sonic test sheet.
  • IA II Blocks come with a full warranty
    for material and workmanship.*

Finishing kit:
Includes all pipe plugs, 5/16 dowel pins and Standard screw in Freeze Plugs. $99.00

Oil Pump Drive Shaft included in price.

IA II Pontiac Aluminum Engine Block:
  • High Alloy
  • ASTM class cast iron block
  • Siamese Cylinder bores
  • Four-bolt steel main caps
  • Main webs thickened to the
    maximum for added strength
  • Wider pain rails
  • Thicker deck surfaces
  • Improved Oiling
  • Solid Lifter gallery with drilled oil returns
  • Lifter feed oil holes tapped 1/4 - 20 for oil restrictors
  • Bronze lifter bushings optional
  • Redesigned cooling with added water
    holes in the back for better water flow
  • All blocks are dry decked
  • Threaded freeze plugs
  • Dual bell housing bolt patterns for both
    Pontiac and "corporate" transmissions
  • Bottom of cylinders are notched to clear
    strokes up to 4.75”, 5.0 stroke possible
    with some grinding
  • Motor mounts for the standard Pontiac
    5-bolt motor mount pattern
  • Accepts all OEM Pontiac parts
    plus many other improvements
   IA II Aluminum Block
Part Number APSJBA
Block Material Aluminum, 2SR Sproniam
Cylinder Wall Type Siamese
Cylinder Wall Thickness .200 (2)
Deck Height 10.240"
Cylinder Bore 4.245"
Number Main Cap Bolts 4
Main Cap Bolts Dowel pinned and splayed
Main Cap Type Billet Steel
Cam Tunnel Options 50 mm or 55 mm
Crank Journal 3"
Crankshaft Seal Any OE or aftermarket 3-inch main Pontiac rear seal
Max Cylinder Stroke 4.75"
(1) A brinell hardness and tensile strength is check on every pour.
(2) .200 thick is a target thickness estimated only
* See our Conditions of Sale  page.

A sonic sheet is given with all blocks shipped.

We reserve the right to change the dimensions
of the block and materials without notice.


Packaging and Handling $4.95 each order
Plus shipping charges

Crating charge for overseas shipping is $125.00 per crate. F.O.B. point of shipment origin.