Ok I'm rebuilding a 1971 Fiat 850s spider. I bought new pistons for it and took it to the machine shop but he could only push the wrist pins out. The rods and pistons were all mixed up and there are no marks on the pistons that mark which way they face on the rods. My question is, which way does the oil hole go on the piston, the bigger side of the wristpin or the smaller?