Engine Blocks

GM Pontiac 4-Cylinder

Nick Arias Jr. Racing Components’ “Max Duty” aluminum 4-Cylinder block provides a true high-performance, lightweight and reliable replacement for the Pontiac 2.5 “Iron Duke” / “Super Duty” and Chevy II. We took our 60+ years of experience building and racing inline engines and created the ultimate foundation for your Midget, Drag, Marine, Oval, Off Road, Dry Lakes and Street Power Plant.

Based on the original Iron Duke platform, we’ve added a list of enhancements to the stock block which are numerous. Firstly, the cylinder head deck and water jacket are designed to accept the Chevy II/Pontiac, but also most any Chevy/Ford/Mopar Small Block and Chrysler 392 Hemi cylinder head bolt patterns. Secondly, the side plate surface can be configured to mate up to whatever cylinder head is chosen. NA Jr. also offers billet side plates to match. Lastly, we’ve taken your input and made improvements for durability and muscle. Check out the list of features below.

Chevy head bolt patterns include Fontana, 23, 18, 15 and 12°, LS Series, Canted Valve, SB2, Corporate 10° and NA Jr. LS-AH Hemi (and most 4.400” bore spacing heads).

Ford bolt patterns include 302W, 351C, 351W, 351M, SVO, Yates and NA Jr. SF-AH Hemi (and most 4.380” bore spacing heads).

Mopar patterns include 392 Hemi and most “A” series 4.460” bore spacing heads.

Part #: 401020-001-01: Chevy II Head - $ 3,200.00
Part #: 401020-002-01: Chevy Gen1 SB Head - $ 3,200.00
Part #: 401020-003-01: Chevy LS-AH Head - $ 3,200.00
Part #: 401020-004-01: Ford Windsor Head - $ 3,200.00
Part #: 401020-005-01: Mopar SB Head - $ 3,200.00

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