I am running cams out of 500EFIs and using thunderbolt distributors that I think came off of mid 90s 350s, I need to know if I need to swap my distributor gear for a bronze gear? I have read that they used crane cams in the blue engines and a steel gear was ok but I do not want to find out the hard way. I would appreciate any info. Thanks

Crane cams that part #'s end in IG have iron gears.

stock dist gear on a 500 efi is iron, at least all the ones Ive seen

i would give crane cams a call but i use a melonized gear with crane hyd roller cams.

bingo

I'm building some 454's with 500EFI cams and for $33/melonized gear it's worth the piece of mind changing it.
Is the thunderbolt distributor 0.491" or 0.500"?

I ran the stock TB IV dist gear with a Crane 731 with no problem for 150+ hrs(sold boat), but that was like 15 years ago.

every one i have seen was .491.