I agree about the 750 being overkill for a 383 for general driveability use. The Edelbrock tech told me the same thing. The 750 would be more suited for a 440HP engine like I have in my 68 Super Bee right now or a hopped up 383 with more cam , head work etc... Mine is stock. The 600 was a better choice as I got to run 2 new ones on it back to back. My issues weren't actual performance related so I got the chance to evaluate from that standpoint. I use new and old age Carters on all my other cars with no problems. All but the stock Holley six barrel I have on my 70RR but those ar two's.