OPRV interchangability between early and late blocks?

[HondaDustR]

OK, another detail crossed my mind in trying to get ahold of a short block is OPRV compatability. I'm pretty sure I've seen there are like 4 different versions of the OPRV, 2 3 piece versions for the early blocks, and 2 one piece versions, one to retrofit early blocks, and one for late blocks.

My car has a one piece OPRV, but how the heck to I tell whether it's the early or late style, and will it work in an early block (I'm looking at a couple of blocks, all '84s). Or will I need to make sure I get the OPRV from the block, in which case, how problematic are the old 3 piece parts and how do I tell if it's the old version prone to corrosion or the updated 3 piece part.

Oh, and I assume the oil pumps are compatable between early and late, but they might not be!

Thanks!

[Schumi]

Do a search for a thread that I started a while ago on OPRV's. In it are pictures of the different types so you can visually see the difference. There are the early style 1 piece, the early update style, and the late style 3 piece.


As for oil pumps, I think your best bet would be to get a short block with original oil pump installed and do not tamper with it. The oil pumps are good for the life of the cars and should never have to be rebuilt or replaced. I think that if there is an oil pump problem (very rare) then the entire shortblock should just be replaced with it as a new oil pump will cost you what an entire used engine can be had for.