.045 - .060 gap for HEI, depending on application AND plug, I would say .045 is a good place to start. I can't remember if it was my 1974 1/2 ton 350 or my 1976 3/4 ton 350 that was stock .060 gap


1957 Chevrolet 5700 LCF 283 SM420 2 speed rear, 1955 IH 300U T/A, 1978 Corvette 350 auto, 1978 Yamaha DT175, 1999 Harley Davidson Softail Fat Boy