Cool thanks! And I’m assuming from the casting number it’s a 71 block right? Would the model year mean it has the cast crank or would it have a forged crank from 71?
well that answered my question, never thought I’d get my hands on a 340 so I don’t know all the specifics but hey I guess the big lettering on the balancer saying,”use with cast crankshaft only” might be a good clue haha.
now here’s another question, if it has a cast crank then is it externally balanced or internally, and if externally balanced do I need a external balance flex plate or converter. Guy I bought it from put different pistons in it and says it’s about 10.5:1 comp and that he had the rotating assembly balanced with those pistons, does that make it internally balanced now? Sorry I’m a newbie when it comes to 340s and I just want to make sure I don’t do anything to hurt this engine.
We just had a 360 here with a externally balanced damper. It was neutral balanced when built and took a neutral balanced flywheel. When you tear it down see if there is a heavy metal slug in the rear of the crank. That was the give away that are motor was neutral balanced.
Yup, if your balancer has that cast into it, chances are it still has a cast crank and is still externally balanced. You would also need the correct matching flywheel or converter, or, a special flex plate to take the place of the weights on the converter. There used to be some weight kits available so you could add the appropriate ones as needed. I don't know if they're still available or not.
