Resurecting an old thread again.

Can anyone tell me what the pitch of the thread is for nuts on the replacement ARP studs?

Often is the case that when studs are used to hold down a cylinder head a finer pitch is used for the nuts.

If that is so then what torque figure is applied for the Dato as a finer pitch would result in greater clamping force for the same torque on the nut as compared to the bolt.

Any thoughts?

Thanks DD,
Looks like ive ordered the right ones then.

ARP is from the land of the 1971-1973 A12.

NOTE: 1974-up A12 and A14 use the same center (long) head bolt.

So
use #202-4202 (A12) for early engines
and #202-4203 (A14) for all late engines, including late A12, A12A, A13, A14, A15

Compare with Head Bolts

Ordered! Thanks heaps.

I think the A14 ones would be the go as you have both late model block and head, the #202-4202 would be for early A12's, where the centre head bolt is an oil passage.

That would be my thinking, the heads are the same height so no real differences in head bolts apart from the one centre bolt.

Hi all, Im wanting to order some ARP head studs and there seems to be two part numbers.

#202-4202 (A12)
#202-4203 (A14)

What would be diferant between the two sets?

I have an A12 block (distributor at rear) and are fitting an A14 head. which kit would i order?

Can anyone help,
Thanks.