Oil Pump Fitment

[MikeG69]

Engine is a 1977 360. I bought the engine rebuilt and did not have an oil pump. I purchased a melling 72s pump.

The mounting neck will not fully seat, which does not allow the pump outlet base to mate up flush with the bearing cap.

There is a "step" (see attached pic) View attachment 1714966625 in the bushing hole that may be causing the problem. I don't have a mic or caliper that I can get in there to confirm dimensions against the pump.

Has anyone else run into this? What's the fix?

 

[diymirage]

What main bolts are you using?
I've heard or ARPs causing interference

Did you remove the intermediate shaft ?

 

[Johnny Mac]

as stated above, Arp studs notoriously hit the housing on the pumps and cause fitment issues. Is this the issue you are having? Your pic isnt really revealing. Let us know.

 

[MikeG69]

Intermediate shaft is out

Standard bolts.

Here is another pic. Ill need to get one tomorrow showing more.

 

[RustyRatRod]

If there is the smallest burr on the pump or in the recess where it mounts, it can be very difficult to get the pump to seat. I would inspect it very closely. You may need to lightly file an area to make it fit correctly. I have before.

 

[MikeG69]

Ill take another look but did not see anything when inspecting before. I may need to put on my inspector gadget goggles.

 

[RustyRatRod]

I use a magnifying glass on suspect items. Lots of times things will pop out.

 

[nm9stheham]

FWIW, the pump housing is not designed to fully seat against the small step in the shaft hole that you show; the housing just needs to engage that hole enough to allow the hole to locate the pump laterally around the shaft axis. It could be a burr as said or the pump is not machined right. Does it go in part way and then stop?

 

[MikeG69]

Thanks for everyone's help.

I was able to get it together today after monkeying around with it.

It's bolted up fine and the pump spins like it should.