So I have a 1969 C50 with what I believe is a 350? (according to Glovebox sticker)

Was running poorly, backfiring through carb and not taking the throttle well.

Saw that it needed ignition work, decided to upgrade to HEI.

Called the parts house, they gave me a MSD Streetfire HEI distributor, said it will work no problem.

Wrong.....

Of course the oil pump drive is different.

Ok, bought new oil pump and drive shaft, removed pan, pump and drive shaft. Figured I'd install the new distributor by lining up the rotor with the mark I made on the firewall and then install oil pump and shaft from the bottom and not have to fight lining up the oil pump drive tangs.

But I can't get the distributor to fully seat? It's sitting up about 1/8" from the manifold?

What am I doing wrong and does anybody know if this combination will work?

I could use some help.

Thanks!

1969 C50 Chevy. 5 spd tranny, 2 spd rear, 14' box and hoist.