tinner

I'm getting closer to installing the 455 into my originally 350 car (1969 Cutlass). I plan on using my factory 350 mounts (both frame pads and rubber engine mounts). My question is will the big block headers fit when using this mount combination or do I have to search out the correct mount combo for headers to work? I know this is an issue in some of the older Chevy's.


Thanks, Jim

oldcutlass

Headers should work fine, however as always sometimes requiring a bit of messaging.

joe_padavano

You also know this is not a Chevy...

I'm afraid this has been covered about a million times here. The crank centerline of the engine (and thus the exhaust port locations of the heads) will be in EXACTLY the same place whether you use the 350 frame and motor mounts or the 400 frame and motor mounts. That means that the headers will fit the same either way. Whether you will have clearance problems with the headers is a function of the header manufacturer, not the motor mounts chosen.