I know the purist out there hate a SBC in a Oldsmobile. Doesn’t concern me, It’s all GM!! But, I am putting a 355 in my 68 cutlass until I build another 5.3 as my current one is going in my S10. The biggest question I have is mounting the engine. It had a 455 in it and I presume has big block mounts on the frame. Will SBC mounts just bolt up or do i need conversion mounts?

 

You will probably have to buy the frame pads and engine mounts for a Chevelle.

What are you doing for transmission ? Dont forget the Chevy bellhousing bolt pattern is different.

 

Thats what I had assumed. I am using the BOP Turbo 400 out of the car with the SBC.

 

For the transmission, you can buy an adapter plate. As stated above you’ll need Chevy frame brackets and motor mounts, Chevy starter, some minor wiring changes because the starter is on the opposite side and sensor positions. You may need to adapt power steering hoses. You may be able to reuse the lower radiator hose but the upper is different. In addition you’ll need new headers and exhaust mods to fit.

 

Thanks much! This is what I needed to know, always been around Chevrolet growing up but not so much olds. The car in question has sat for 26 years untouched by my grandfather and I finally convinced him to let me purchase it.

 

Depending on what rear gear is in the car you might be better off with a more modern OD transmission behind the small block. 200R4 would probably work good.

 

Already have 400 on hand and not much funds for a new transmission

 

Did your Grand Father put the 455 in the car, because the only Cutlass/442 that came with a 455 in 1968 was the Hurst/Olds, of which there were only 515 sold.

 

Where did the 455 go? It would probably be simplest to use that or another one, seeing as the car is already set up for it. The SBC swap seems like one of those propositions where you can spend a lot of money trying to save money using parts on hand just because they're there.

Plus, it'd have to be a pretty well-built little Chebby to beat a 455.

 

He bought the car as is and the 455 came with, with a burnt up crank. It’s a typical run of the mill cutlass with 442 badges. Already vin checked and it is indeed not a 442. Potentially a clone wannabe when he bought it. The motor was built at a performance shop in Clinton whom has since went out of business, and made 993 HP to the flywheel. Previous owners had the engine built, and attempted to seal a terrible leaking oil filter with an extensive amount of silicone.

 

Running 350, 750 Holley, dual plane edelbrock intake, 993 cast heads, lunati voodoo .525 .546 lift cam, .030 over balanced rotating assembly, forged rods + pistons. Just a good smooth SBC to put in til I can afford to rebuild the w30 that was in it. It’s sat in a garage corner collecting dust and moisture for 26 years. Already.060 over so it’ll need sleeves as well as everything else. The only things salvageable right now are the heads, intake, block, and pistons. Maybe the rods. It needs a lot of $ that i currently don’t have to spare haha

 

Sounds like a nice Chevy. I would see if you can sell it and put the proceeds towards building the 455 now, rather than sometime down the road. This would save you the time and trouble of switching everything over for the SBC and then switching it back again when you go to reinstall the 455.

Plus it would probably make Grandpa happy.

 

Wow, 993hp 455, any details on the build?

 

I wish I had full details of it, I will know more about the engine once I get it all pulled out of the corner and see what all is there/what was done to it!