I need a flexplate for a '60 348 chevy. Are these internal or external balance? What, if anything, is usable from a SBC or BBC ?
HI, 409 and 348 "W" engines are internal balanced engines, the small or big block flexplates will work fine. You just need the right diameter for the starter to match.
Here's a thread in the Tech section that will help you with inter-changeable parts, http://www.jalopyjournal.com/forum/showthread.php?t=78281&highlight=409 Terry