95ONE

iTrader: (1)

I need to drill out a ring gear (flexplate) for my starter. 153 tooth, not a 168. It gives more ground clearance, among other things. I am only using it to start the motor. Custom clutch stuff coming in from Tilton. - I do not have anything to compare to. I never had a flywheel or flexplate since I've bought the motor.

3.15"? Every 72 deg? It looks like on hole is not in line with the other 4 as far as the degrees. Every 72 deg on center, but one is like 65 degrees? Edit: They are all an even 60 deg apart, 6 bolt -

I googled and searched. Not much in ways of answering true pattern, just swappable parts.

95ONE

iTrader: (1)

No one?

95ONE

iTrader: (1)

well, I guess an hour and a half of parts removal, then checking and re-checking was un avoidable.

For those that search later and find this thread that want to know for whatever reason.

3.1" on Center for flywheel bolts. Every 60 degrees - Even 6 bolt pattern. 1/2" Diameter Bolt holes. Disclaimer; What I measured. GM official measurements were never found. Someone else on here measured 3.15" Diameter on center fwiw.

I said 72 deg thinking 5 bolts like on a wheel. I've been messing with that a lot lately and I'm embarrassed to say that was stuck in my head. It is indeed a 6bolt (easy part)

chrisfrost

iTrader: (8)

Ya ,,,,,I was gonna say just make a template for it it should be pretty straight forward . I am putting 12" rotors originally were gonna go on My 1980 Z-28 but now are going on an El Camino so I made a template 4 the 4.75" 5-lug bolt pattern marked and drilled the holes ,,,,,,,,,time consuming 4 sure I also turned the hub down from I think 3.125" to 2.75" or whatever it is .