I'm having some trouble with my 74 c10. I had a 2bbl intake, but when I started rebuilding, my uncle gave me a 4bbl. I've got it all back together, but the distributor wont seat all the way down. I put a high volume oil pump and a class B cam as part of my rebuild. I tried turning the pump shaft with our pre-oiler, but it's liking 1/4 inch from sitting all the way. Could it be that the manifold being off a an 83 305 wont line up with the cam and pump? What do you guys think? Robert