Just recently bought 69 cutlass convertible with a 350 rocket,350tran. Someone started a H/O replicia, except black base instead of white. Wanting to drop a 455 in there, been doing a lot of forum reading. Just picked up a 70 455 rocket(e heads) and trans out of another car. Plan on shipping to a selected machine shop this winter for next winter project. What advise can you give me ? I believe i will have to use the 400 t yoke from donor car, motor mounts from either but dont mix them. shorten driveshaft or find an A body 400turbo shaft. will w/z manifolds allow me to run duals or should a look at headers. Not familar with Olds, been a chevy dragracing man and now its time to cruise and enjoy my new Olds. I would appreciate any advice on motor swap.

 

Sounds like a fun project! Did your 1970 455 come with a long tail shaft TH400? That's what was used in full sized cars but the A-body came with a short tail shaft. What's your plans for the car? If it will see a lot of time on the drag strip I'd go with headers. If not I'd go with W/Z manifolds. If you just want a strong street car go with a cam designed for that, 9:1 to 9.5:1 compression to run on pump gas, and if the heads don't have the 2.07 intake valves have them installed. You can also get some nice gains by working the heads. There's a lot of guys here who know more about that than me and they may even recommend a specific shop to do that work. I like the performer intake but I know there's a couple others that will up your performance over the stock one. These are just some thoughts, but if your new to Oldsmobile I'd recommend purchasing a book described in this thread:

https://classicoldsmobile.com/forums...ance-book.html

It will provide a lot of information on Oldsmobile engines. John