So i was recently given a set of 20 over flat top SBC 350 Pistons. I have tried to do some research but have not been able to come up with anything. The only markings on them is P-1505, M-19A, and IND BRAS. The number matches an engine tech number but those are dished Pistons while mine are flat top, so it is not those. Any one have any idea ? not sure if I will ever use them but they are in really good condition and I would like to know incase I ever need them. Thanks