Does anyone happen to know the dimensions of the FA20 head studs/bolts? They are an 11mmx1.25 thread, but I am curious to know the length as compared to EJ head studs.

I am rebuilding the original Perrin EZ30 Gen 2 motor, and when it was build the block was tapped to accept 11mmx1.25 head studs. (Factory is 10.5mm). Since Jeff didn’t have time to get custom studs made, he used ARP EJ head studs with a spacer. I’d like to find another ARP 11mm stud that is shorter.

ARP does now make 10.5mm EZ30 Gen 2 head studs (sold by Outfront), but this block has already been modified for the 11mm size.

In the picture attached, you can see the factory EJ, ARP EJ, the Perrin modified ARPs, the factory EZ Gen 2, and an ARP EZ Gen 1 (which must have been custom since they are not in the catalog).

If you look at the catalog picture of the FA20 ARP studs, they don’t have the extended tip, and look to be a tad shorter.

(Jr Junior Barrios, Clark Turner, Jeff Perrin,Mike McGinnis, Timothy Bailey?)