I have a dilemma here. I have this old chevy truck that I bought and it has a TON of redneck crap that I'm basically reversing. The truck had a knocking sound and I figured it was the flexplate. Well it was indeed cracked, so I removed it. It looks like a 400 flexplate to me because it has a counterweight. I've attached a picture of it.
I know the engine has been rebuilt, and the casting number (3970010) says it's either a 327 or a 350. I'm concerened/hopeful that this is actually a 383 (400 crank in a 350 block), so I need to figure that out so I can get the right flexplate on it!
I've heard there are externally visible differences on a 400 harmonic damper? Any ideas? Help me figure out what the hey this thing is!