78 block


New Member
May 7, 2013
I just bought a complete 78 231 turbo motor from a friend for $180. Turns out the block is bad (not even upset at that price). My question here is do i need to find another 78 turbo block, or will a N/A block work?


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Charlie, are the 78 turbo blocks even different at all from the NA blocks? Like, is there a distinction between the two in that year, or are they the same?

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What is bad on your block?
Any even fire RWD 3.8 Block will work with that setup.
12966462_10208498902765505_1056849291_n.jpg just rusted out. The guy said he bought a regal new in 78. Didn't like the lack of power took the v6 out in 1980 and disassembled it to see if something was wrong. bought new pistons and rings and gaskets for it and ended up going a different route. Built a 350 and just let the v6 sit in a barn for 30 years. There's a guy here (Nebraksa) that has 43 acres of G bodies and A bodies. I know he has a block, just needed to be sure the n/a block will accept the internals.
If you can find a 4.1 it will give you some extra power but the pistons will be a bit pricey compared to the 3.8. Same basic engine, just a bigger bore. All the even fire RWD Buick V6 engines from 77.5 up to the late 80's are the same, except for the bore of the 4.1.
That block doesn't look that bad. The lifter bores can be honed and the cylinders bored. I just got a 4.1 that was way worse than that and it cleaned up nice.
That Block will clean up & look like new with the "Bake + Shot-Peen" method of cleaning.

You will have to renew the bore surfaces by either increasing the bore size or you might get lucky & be able to hone them.
You guys think these holes could be repaired? That's my main concern. I was impressed with how the heads cleaned up. So if i'm able to salvage the block, I'll be a happy man. Also I've seen the chrome carb hats before, but this guy appeared to chrome quite a bit from this motor. Were chrome aftermarket parts available? Or did this guy chrome the oem parts?


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I believe that you are looking at the normal oil drain back holes. I would take a die grinder & debur the perimeter of those holes. Then have the Block baked & shot-peened.
Those holes look bad to you, but they're not. That's just how the oil drain hole looks on those blocks. It sounds stupid, but they didn't really care how they looked, only that they functioned well enough. You can clean them up a little like JM said, but that's just that how it came from the factory, so it's nothing to worry about. They look nicer and more neat on the newer blocks.

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