[Sick467]

As I was rotating my enigine on the stand so that the old pistons could be dropped out the photo'd washer fell out. I was lucky to have noticed it with all the grime and gook on the floor. I'm betting that it goes on the oil pump drive shaft, but where exactly would be nice to know. Anybody have the details?

[Icerat]

That is exactly what it is. You don't need to worry about putting it back on because when you have the engine apart you should always replace the oil pump drive shaft with a new one which will have that already installed. It goes on the shaft on the bottom half above the pump and close to the block to keep the shaft from lifting out from the distributor end.

[Putt]

Icerat has it pegged, I would only add that you NEED to replace the oil pump drive shaft and use one of the heavy duty ones available.

[Sick467]

Good info guys, thanks. And, yes the oil pump and all it's components will be replaced with modern/heavy duty parts. I assume a new shaft keper will come with the new replacement parts.