Pressure Plate Bolts

Does any one know the thread pitch of the pressure plate to flywheel on a 72 304?

 

My 74 6 cyl 258 has 1/2-20 x 7/8" thread.

 

Not sure, but I think they are 3/8x16tpi

 

You have the engine out. Likely it's a common diameter and thread count. Measure the bolt hole diameter with a vernier caliper. If you've lost the original bolts, go to your local Ace hardware and get a sample of each to try. Typically there are only two possible thread counts, USS (coarse) and SAE (fine).

 

FYI those are special shoulder bolts specifically for clutch cover use.Probably 5/16" or 3/8" course thread.ARP has the bolts you need .Do not use hardware store bolts of any type.

 

Yep. Absolutely not the place to use hardware store bolts. My guess is also 3/8-16 and I would get a set from ARP.

 

Mr. Gasket 910 Mr. Gasket Pressure Plate Bolts - 3/8-16

Note that these have the shoulder on them that MikeStarck referred to above...this is what keeps the pressure plate properly positioned so it's important.

 

Thanks all I was asking at the time I was looking to get replace the one I have and what I found was that there were 2 thread pitches 16 and 18 were listed. Thought that was strange so was asking.