Is the flexplate different between a 350 and a 383? I know balancer is, I just bought my 383 balancer, but what about the flexplate? I was looking on ebay and some look like they have a weight on them and some don't(generic pictures?). So do I need a specific flexplate? All the ones on Ebay are 2 piece rear main and I need 1 Piece. The only one on Ebay that says 1 Piece says 350 and 383 in the title so who knows.