Which 400 should I use?
Alright so I bought a 79 T/A project to rebuild and restore back in April. The 400 block in it isn't the original but is a YX code block. It runs but it still needs some tuning.
When I bought the car the man gave me an extra 400 engine block with 6x heads for free. I did some research on it and if I'm not mistaken it came out of a 1970 GTO Ram Air III car.
Here's the numbers I found...
Engine Code 0613314 YZ
Block Cast # 9799914
Block Date Code E280
Block Vin 20L110143
The heads have a date code H297 so they aren't original to the block.
So the question I'm getting to is; if I'm not concerned with having original parts anyways, which motor would give me better performance if I were to drop it in my T/A? Thanks