Short Block Builder Kits with Butler Supplied Pontiac Block (Ready to Assemble)

Short Blocks (Assembled and Unassembled Kits) - Short Block Builder Kits with Butler Supplied Pontiac Block (Ready to Assemble)

Pontiac V8 Short Block Builder Kits with Butler Supplied Pontiac Block (Ready to Assemble)

Bottom End in a Box — Short Block Builder Kits with Butler Supplied Pontiac Block (Ready to Assemble) for Pontiac V8s

A Short Block Kit (SBK) is the bottom end of a Pontiac V8 and nothing else: a fully prepped block plus a balanced rotating assembly — crank, rods, pistons, rings, cam bearings and main and rod bearings. There is no camshaft and there are no cylinder heads in an SBK. The parts ship unassembled so you or your machine shop does the final build.

These are the kits where Butler supplies the Pontiac block, so you are not out hunting a core first. Butler builds them on 350, 389, 400, 428 and 455 castings plus the aftermarket IAII, and every block goes through the Butler Process before it is boxed.

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Pontiac V8 350 Block Small Bore, Long Legs — 350 Block for Pontiac V8s The Pontiac 350 is the light end of the 3.00" main family, and it is the casting people reach for when the car...More Details »
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Pontiac V8 389 Block Keep the Casting, Change Everything Else — 389 Block for Pontiac V8s The 389 is the GTO-era block, and for a lot of owners keeping the correct casting in the...More Details »
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Pontiac V8 400 Block The Default Stroker Base — 400 Block for Pontiac V8s The 400 is the block most Pontiac strokers get built on, and it has the widest range of anything Butler...More Details »
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Pontiac V8 428 Block The Big-Journal Block — 428 Block for Pontiac V8s The 428 is the big-journal block from the tail end of the muscle car years — a 3.25" main casting like...More Details »
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Pontiac V8 455 Block The Most Cubic Inches Pontiac Ever Cast — 455 Block for Pontiac V8s The 455 is the largest factory Pontiac V8, and it starts with the biggest bore and the 3.25"...More Details »
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Pontiac V8 Aftermarket Block Past the Factory Casting — Aftermarket Block for Pontiac V8s There is a point where a factory Pontiac casting runs out of cylinder wall and main web, and...More Details »

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More About Short Block Builder Kits with Butler Supplied Pontiac Block (Ready to Assemble)

1. What is in the kit, and what is not

Butler builds these kits to a fixed definition so there is no guessing about what shows up on the pallet.

Prepped blockcleaned, magnafluxed, sonic tested, completely deburred, bored and honed with a torque plate, line honed with ARP main studs, square decked, with cam bearings and brass freeze plugs installed.
Rotating assemblycast or forged crank, I-beam or H-beam rods, forged pistons, Total Seal file fit rings, performance rod and main bearings, balanced internally as a set.
Not includedno camshaft, no lifters, no timing set, no cylinder heads, no gaskets, no oil pan and no intake. Add heads and it becomes a Long Block Kit; add the cam, valvetrain, timing, gaskets, oil and intake and it becomes a full engine KIT.
Unassembledparts are shipped ready to assemble. Final clearances and assembly are your shop's job, and Butler will talk your machinist through the numbers.

2. Picking the block you want under it

The subcategories here are split by casting because the block sets your stroke ceiling, your bore range and what the finished engine will displace.

350 and 389 blocksthe small-bore, 3.00" main castings. Good for a period-correct car where the displacement stamp matters more than the last twenty cubic inches.
400, 428 and 455 blocksthe mainstream stroker bases. The 400 has the widest stroke ladder Butler offers, and the 428 and 455 use the 3.25" main journal.
Aftermarket IAII blockwhen a factory casting runs out of cylinder wall or main web, the IAII is where you go for 505 to 541 cubic inches.
Budget 557 castingthe 557 model 400 block is offered as a budget short block kit and is limited to 4.000" stroke and under 500 horsepower. Plan past that and start with a different casting.

3. Finishing the engine

Order the SBK knowing the rest of the parts list is still ahead of you. Tell Butler the heads you plan to run, or the head casting number and chamber cc, when you place the order — piston choice and final compression get settled at that point, not after the pistons are already hanging on the rods.

400 Block 428 Block

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.