All the engines for 1974 and newer (July 1973) use the newer oiling system. The oil goes through the block around the center head bolt. This is why the center bolt differs between early & late engines. It doesn't matter what size the engine is. These are the mid-distributor engines.

For 1967-1973 engines, the oil went from the block through a special galley into the head. The center bolt was still special though, it was thinner than the others.

In both cases, oil must be able to flow around the center head bolt (or stud):


ARP studs should all be thinner in the middle of each bolt, as are all the '13' chromoly steel bolts from Nissan.

You should have the one that needs the longer bolt/stud for the middle oil hole. See my post on A15 uses longer bolt, it's easy enough to measure. You could wait till you start on the engine to be sure, should be able to get the parts in a couple of days.


Tom

Looks like I need the 202-4203 as mine is the later model A12.

ARP

A12 ARP VS A14 ARP

Thanks Peter!

Quote:

Hi Peter,

Thanks for the info mate. To be honest, I don't actually know what my block has. I haven't taken it apart yet...I'm beggining my parts collection first.

It appears mine is the later A12 with the dizzy in the middle? Here is a pic...

Joe,
The #202-4202 has 10 studs of the same length (like in the early A12 with the distributor up front), while the #202-4203 has one longer stud to fit into the middle bolt hole that is recessed into the block beside the oil passage.

Does the 1976 A12 block use 10 same length cylinder head bolts or does it have a longer bolt in the center on the spark plug side?
Peter

thats one for Bige!

Hey guys,

Might sound like a silly question but here goes.

If I'm fitting a H89 A14 Oval Port Head to my '76 A12 Block, which ARP head stud kit do I need?

The one to suit the A12 (# 202-4202) or the one to suit the A14 (# 202-4203)

Thanks,
Joe