As I understand it, it was only the 58 HEADS that were the concern; the blocks were fine. I would like to have a W-motor, 348 or 409, either one, just for the uniqueness of them. Same mounting as SBC/BBC. Years ago, there was a Bracket Racer at Bremerton Raceway with a 67 or 68 Camaro, with a 409 in the car. Very different to see a W-motor under that hood. Go with the 348! I am Butch/56sedandelivery.