Well I have been messing with it for like 2 hours now. I know for a fact it isn't the cam gear because I took the gear on the distributor off and put teh distributor in like that and it sat right inside the oil pump shaft and was still like 3/8" s above where it should sit on the manifold.

The only other thing I could think of was that maybe I have the wrong oil pump shaft in there. I would think that all SBC use the same oil pump shaft right? The 400 one is not different is it? Maybe there was the wrong one in the box at the parts store.

Anyone got any ideas? thanks

BTW I don't know if this helps but I am using a 91 camaro dist, in a 400 SBC. on a superram baseplate.

 

As the distributor gear mates with the cam distributor drive gear, the distributor shaft turns. The oil pump shaft isn't quite lined up correctly, so the distributor doesn't slip down into the slot in the oil pump shaft.

You can either turn the oil pump shaft slightly with a big screwdriver or primer tool, doing that until everything aligns and you can drop the distributor in, or, get the distributor in the right place (gear-wise), let it sit there and turn the engine until the shafts line up and the distributor drops down.

Personally, I prefer the former method, but either will work.

 

I have installed distributors before and that is why I thought this one was odd. So I removed the gear on the dist and installed it that way. The distributor was still 3/8's of an inch too high. So I know it wasn't the fact of it not lining up. the dist went in the oil pump shaft and stil didn't seat.

 

sometimes the lower opening does not have a chamfer to allow the dist to drop down.. but, i would think it would be higher than 3/4" if that was the case.

 

You DO know the 400s use a different oil pump shaft right ? It's necked down quite a bit to clear the cam lobes. I woulnt use a regular one in a 400. Not for the measly 4 dollars the correct one costs!

 

I have always done like what five7kid said earlier. That has almost always worked for me. Some times it drops right in and other times you have to screw around with the oil pump drive shaft. make sure on the oil pump end of the drive shaft, that the groove is enguaged the oil pump. that groove is about 3/8 of an inch tall. Some times crud holds the shaft to the distributer and lifts it off the pump on some engines.
Also one time on a poniac 400 I was putting in a distributer. I had a space of about 1/4 and 3/8 between the intake and the distributer housing. I messed with it forever and finally said screw it and just tightened down the distributer clamp thinking for sure I was going to bust somthing, but it didn't break, it sat down like it was supost to. Dunno why though.

 

I'm not trying to flame, but tightening down the dist. bolt clamp and trying to force the dist down is a BAD idea. That could require an engine teardown if it's something more than burrs on the dist shaft or intake.

 

Yeah,
I know it wasn't the smartest thing to do. It was getting late and we (the cars owner and I) had been messing with it so long, he just grabed a wrench and looked at me, I shruged my shoulders and he tightened it.
He is still driving it so I suppose it didn't hurt anything too bad...I hope anyway. believe me it's not a common practice in my garage. I'm not sugesting it to anyone. Good luck

 

Actually it ended up being that the auto parts store gave me the wrong one. They gave me a shaft for a Big Block chevy and it is like 3/8 of an inch longer than a Small block Chevy.

 

That'll do it...

 

just so this never happens to anyone else. IF you go To Autozone and look up parrts for a 1975 chevy truck with a 400 SBC it will list the wrong oil pump shaft! it will list a BBC oil pump shaft.

 

darn autozone! They probably thought you were talking about the 402 bigblock. oh well, glad to hear you go that taken care of.