Inliners International Forums General Discussion Engines Distributor not seating

Hello guys, I just recently bought a new 250 motor and I'm having a hard time getting my distributor to seat on the block. I didn't have this problem with my old 250. I believe the older one was a 70, and this one I believe it's a 72 or 74. I don't think this should matter.
The new motor came with a new oil pump which I used of course. Is this my issue? What's different about it? And how can I fix it?

I did look down the hole and turn the shaft a bit but everytime I tried seating the distributor it fail. Almost seems like maybe it could be a bit longer?

How much farther does it need to drop in? It sounds like it is not lining up with the slot in the oil pump. Is it a stock distributer? Is it a stock pump? First I would try to turn the rotor or the pump 180 degrees and see if it will go. Doe you have another distributer to try? Can you feel it engage and drop into the cam gear? Just some thoughts.

So it's not the stock one. It's an HEI distributor that I'm using. Worked fine with my old motor and oil pump. I did tried rotating the rotor as well as the pump and nothing. I wonder if it's too long for this pump? Maybe the one that it came with its different?

One issue can be if the dist is in the pump and engaged fully in the gear. The issue can lie at the block Some blocks were machined to much at the factory, I have seen this issue Only a few times. So that is possable the way to fit would be to shim the dist.

Thank you Larry. I don't think that's the case. Something tells me that they sent me the wrong oil pump. Unless there's only one type.

Sense this distributer worked in your other 250 it is probably not an early style distributer. I can not remember which way it works but those can be swapped only one way probably because the vacuum advance is external on the early distributer and spaces it a bit higher.. (216, 235, 261)

The Chevy 6's all used the same oil pump. But, there are oil pumps from 4 cyl 151's that will fit but use a different drive tang.
Your pump should have been a M62
It only should have 1 slot for the dist to fit in and drive.

I actually got it to seat last night. I just took my time and kept working at it by turning the pump with a flathead. Thanks everyone for your help.

Good! Sometimes they just take some messing with to get them to drop in. With a close fitting slot and gears to engage it is not always easy. We see problems where there aren't any.