Trying to get my 1970 455 to fire. The distributor doesn't seat all the way down. The oil pump drive rod may not be letting it. Not sure. I fit the distributor into another motor and it fit fine. If the drive rod is the problem what is the fix? If the distributor gears are he problem then what is the fix? Thanks.

 

The distributor is rebuilt with new O ring.

 

Have you got another distributor to test fit?

 

Rotate the engine (with the distributor engaged in the cam gear) until it rotates enough to align the oil pump drive hex. The distributor will drop down. Alternately, pull the distributor, turn the oil pump drive shaft slightly with a 5/16" hex socket, and try again. This will be a lot of trial-and-error, which is why I just turn the motor. This is common when installing a distributor.

 

O ring needed lube. So the distributor is now where it needs to be. Now the new repro starter won't engage the flywheel. Dang.