- Home »
- Catalog »
- Rotating Assemblies & Stroker Kits »
- 400 Blocks (406-495 cu. In.) »
- 400 Super Stroker Rotating Assemblies- up to 4.500 Stroke
400 Super Stroker Rotating Assemblies- up to 4.500 Stroke
Pontiac V8 400 Super Stroker Rotating Assemblies- up to 4.500 Stroke
Past 480 Cubic Inches — 400 Super Stroker Rotating Assemblies- up to 4.500 Stroke for Pontiac V8s
Super stroker is what Butler calls the longest cranks a block will take, and in a 400 block that means 4.375" and 4.500" stroke packages. This is where a 400 casting stops being a 400 in any meaningful sense and starts making displacement that used to require a 455.
Butler builds balanced 471-480 ci and 487-495 ci rotating assemblies for the 400 block at these strokes, alongside Eagle flat-top 4.500" stroker kits at 488 and 495 ci.
Browse 400 Super Stroker Rotating Assemblies- up to 4.500 Stroke Products
Popular Brands:
More About 400 Super Stroker Rotating Assemblies- up to 4.500 Stroke
1. The combinations
Two strokes live on this page, and they land in different places.
| 4.375" stroke, 471-480 ci | Butler's balanced rotating assembly for the 400 block. The half-step, for builders who want most of the displacement without going all the way to a 4.500" crank. |
| 4.500" stroke, 487-495 ci | Butler's balanced rotating assembly and the top of what the 400 block holds here. |
| Eagle flat top 4.500" kits | Fixed combinations for the 400 block at 488 ci and 495 ci, with forged 4340 rods, ARP 8740 capscrew rod bolts, forged Mahle pistons and file-fit plasma-moly rings. Supplied unbalanced, as all Eagle kits are. |
2. What changes at this stroke
A 4.500" crank in a factory 400 block is the most demanding thing on this shelf, and it asks for more than a parts order.
| Block selection | Casting numbers ending in 557 have thinner main webbing. Butler suggests limiting those to 4.000" stroke and under 500 hp, which rules them out of this page entirely. |
| Clearance work | Long-stroke Pontiac combinations need the block checked for rod and counterweight clearance. Mock it up; do not assume it drops in. |
| Balancing | Every assembly must be balanced before it runs. Butler balancing weighs and pin-fits rods and pistons, computer balances the crank to the assembly and documents it on a balance card. Internally balanced assemblies need a neutral flexplate or flywheel and a neutral balancer. |
3. Matching the rest of the engine
| Compression and fuel | Chamber cc drives the piston. Tell us the heads and the octane you will run and the piston gets designed to hit that compression; custom dish pistons carry a 10 to 12 week lead time. |
| Airflow becomes the limit | Once the displacement is there, the heads, cam and induction decide what it makes. A super stroker under stock-port heads gives up most of what you paid for. |
If you are this far into a 400 block, it is worth a phone call before the machine work starts. We will go through the block, the heads and the intended use and make sure the stroke you order is the one the combination actually wants.
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.