No. they are different head designs.
Pontiac 455 headers generally do not fit a Buick 455 due to differences in the engine's exhaust port locations and bolt patterns. While both engines are part of the General Motors family and share some similarities, the specific design and dimensions of the exhaust manifolds and headers vary. If you're looking to upgrade to headers for a Buick 455, it's best to choose headers specifically designed for that engine to ensure proper fit and performance.
Several companies manufacture headers specifically designed to fit a 455 Buick engine, including TA Performance, Hedman Hedders, and Doug's Headers. These manufacturers offer various designs and materials to optimize performance and fitment for enthusiasts and restorers. It's important to consider factors like intended use, exhaust system compatibility, and any modifications when selecting headers for a 455 Buick. Always check for specific compatibility with your vehicle's year and model.
The 455 will fit. The transmission might have a shorter tailshaft, though.
yes
No, the blocks are different.
yes
Yes
No, 350 headers will not fit directly on an Oldsmobile 403 engine. While both engines are part of the GM family, the Oldsmobile 403 has different exhaust port configurations and dimensions compared to the Chevrolet 350. To use 350 headers, you would need specific adapter plates or custom modifications to ensure a proper fit.
No, Not even close.
No.
The 455 engine can fit into a 1969 Buick Skylark with some modifications, as the Skylark was originally designed to accommodate smaller engines. You'll need to ensure that the engine mounts and transmission are compatible, and may require custom headers or exhaust modifications due to space constraints. Additionally, consider upgrading the cooling system and suspension to handle the increased power and weight of the 455. Overall, with the right adjustments, the conversion can be a rewarding project for performance enthusiasts.
I put a 455 in a regal.. and it was a snap. get the right mounts, i used factory steel from a 73 centurion 455. then used A body headers ,u half to drill new in the frame ... noithing will line up so dont bother trying.if all goes well for you, the reward is cant be be beat