I have a small collection of Y block parts and engines and noticed that in that pile I have two different length pushrods. The motors these came from were a '57 T bird motor, a '59 or '60 "car" motor and a '60's truck motor that has been rebuilt and may not have the stock parts. So what is the correct length pushrod for which motor? Some are about 8.125" overall and some are 8.258" long. I know these stock pushrods are weak and should be replaced and I see the two different lengths sold just don't know which to buy. I'm building the '57 T bird motor with "G" heads and high ratio rockers. Any difference in the ball or socket size?