Hi,


i bougth a 75 Oldsmobile CC. How can i be sure, that is really a 455?
And is it a th400 trans?
I have read of this 12 bolt rear axle, what is the particularity?


Arvid

 

Look for this number above the water pump




Yes. That's the only trans installed in the Custom Cruiser that year.

That axle is unique to the full size Olds and is NOT a "Chevy 12 bolt". Parts are difficult to get.

 

Hi and welcome to the forum! Your Custom Cruiser looks to be in great shape, nice find!


What's the VIN? (Vehicle Identification Number). If the 5th character of the VIN is a T, then it's a 455 car.


Of course, engines do get replaced so you can also look at the letter cast on the heads. It should most likely have a J. If it has a number instead of a letter, then it's a small block which is unlikely. I believe some '75's had 400 engines.


Post some pics of the engine, VIN and head castings. You'll get the information you need on this forum for sure!

 

Heads can be replaced also, which is why I showed the casting number on the block.

 

Good point! Can you actually swap small block and big block heads? I've never even needed to pull a head so I really don't know.

 

Yes you can. They are geometrically identical. Of course, you can also bolt J heads to a 400 or 425.

 

Hi,


yes the 5th character ist a T. Very good.
Yes the CC is in a great shape, Need some work inside. The carpet is ugly. Great driving, need some more power ;-) but a good cuiser.