That has absolutely nothing to do with it. The 455 and the 350 sit the exact same height above the crossmember using different mount configurations. And they installed them from the factory, but they are not required. I have had standard valve covers on my 1970 442 and they clear both the power brake booster and the A/C box.

Olds just used different frame and engine mounts between the BBO and the SBO. The location of the engine in the car is the same.

Under your logic the 350 only needed the taller foam for the OAI hood due to the engine mounts. It's all in the deck height.

Also under your logic installing headers on a 455 that is on 350 mounts wouldn't work, but whadda know....it does.

It would also require a different fan shroud between a 350 and 455 equipped car due to the 350 sitting lower (according to you) and guess what...YOU DON'T.

So just give it a rest already and let the guy drop his 455 on the 350 mounts and have a good time with it. There will be no fitment issues at all.

 

this board is a waste of time

 

Everything svnt442 has answered is true. A swap from a 350 to 455 is pretty strait forward. Nothing special needed Just take the 350 out and bolt in the 455.

 

Hey SVNT442 you sure shed alot of light on this engine swap, and as well as everyone else's input. Now your telling me I can use OLDS 350 headers on this 455! Man this swap is becoming alot easier to deal with. Thanks alot. As for any disagreeing with any postings, just let it go. This is supposed to be to help each other out, lets keep it that way. I've worked on alot of chevy's but never any original Oldsmobile models so this forum has been great.

 

NO NO NO NO!!!! You need 455 headers because the 455 is taller and wider than the 350. SBO headers MIGHT bolt to the block out of the car, but would hit just about everything in the car.

You can get some inexpensive headers from Summit, or you can get some better ones with thicker flanges and/or a ceramic coating. It's all up to you.

Just remember headers are not interchangeable between SBO and BBO.

Good luck and have fun!!