258 oil pumps

[Tinman22]

Does anybody know the difference between a AMC 258 i6 / 4.2l pump with the tab on the cover and one without?

I can't seem to find it anywhere.

Block is the heavy casting (pre 1980) and the pump had no tab.
The pump I want to use has the tab.

It came off of a later light block. The only diff I can see is a slight pickup angle. But I'm going to use the pan from the later block.

Any ideas?

 

[caveman]

It should work ok if you use all of the parts that you listed. They changed the oil pumps over the years, but they all bolt up. I have an 80 CJ with a 93 Grand cherokee pump in it. I also had to use the GC pick up and oil pan.

 

[Tinman22]

I figured as much.

I've heard that there was a volume diff. Post 81 vs pre 81.

It's new and I got it for free so in it goes.

 

[gutthans]

It's not the pump body, it is the pickup tube and the pan design that must match. (e.g. can't use the late 4.0 pump with the mid 80's CJ pan because the sump was relocated)

I think there is a concern with the proper filter however due to a change in the pressure relief valve. You should match the filter to the block year. I believe some blocks are pressure relieved in the block (spring and plunger) where other (late) models depend on the filter internal bypass to release.