There is a '75 455 for sale locally, the guy says it runs and he just pulled it from his Riviera he's asking $300 for it and another $100 for the trans. I plan on re-ringing it and putting 430 heads on it. My question is, can you put '70 pistons in a '75 block? Should I bore it and get it align-honed or should I just put different pistons in and go with it? One more dumb question, should you replace the main and rod bearings while you have everything off? Thanks, Philip
I wouldn't re-use any piston. Before you make any decision the motor needs to be torn apart, magged, and get a full spec. that will answer your questions...
I have a 32 year old block on my engine stand that has .002 of bore taper on its cylinders. I am installing a 75 crank and pistons in it and using the original heads, unworked. ( the main benefit of High Nickel castings) Don't over-engineer. If the bearings are clean and the compression is within 10%, high to low, put a new oil pump on and run it. Build it when it wears out. (which may not be in your lifetime.) The beauty of old American iron is it's relative cheap cost yeilds tons of bang for the buck. If you are going to spend, as suggested above, just go buy a crate motor and save yourself a bunch of bruised knuckes and brain damage. Do research on the head compatibility with the newer block. I had to revise my project because the 75 block has enlarged water jacketing that the older heads do not appear, to me, to cover. Someone in this group said it will work with the newer gasket but I lined them up and didn't see enough material on my heads to compress the gasket required on the newer block. BTW, the price is great, got my 455 and T400 for $250.00 but ended up having to turn crank. See ya, Tom.
I have reringed a 70 before and got another 80,000 miles out of it (drove it hard till i put a rod threw the block), a am in the process of reringing a 72 block and am swaping 70 pistons onto the 72 rods . with both moters i had the pistons maged and miked and checked the block to see if it was good for just a hone, , then had the rods reconed and the crank tuned. the buick pistons are pretty tough and can take being use over and pressed off and on to another rod, but like i said they have to be in good shape to start with, just my 2 cents Kelly
Thanks for all of the info. The person I'm trying to get it off of said somebody took the whole car home and told him that they would bring back the engine and trans. Thanks, Philip
It all depends on money. I have re-ringed some engines because I didn't have the money to do otherwise. I used 70 350 pistons in a 73 block once without problems. Check it and make the decision according to how often it will be driven and how much cash you want to spend. I have used 67 heads on later blocks too. Plug the oil holes or you will have a nasty valve cover leak. Not too familiar with mid 70's blocks, but someone here has done it for sure so wait for more posts.
