Q: I have a 350 Chevy engine that’s basically stock but is bored .030-inch over, has flat top pistons, and an Edelbrock Performer intake and 600 cfm carburetor.

I just put in a COMP Cams Magnum 292 Series cam with new lifters, valve springs, retainers, etc., plus roller rocker arms. My oil pressure has dropped from 60 psi to 30 or 35 psi. Where did I lose pressure, and how do I get it back? I did not nick the cam bearings when I installed the new cam.

1974 Chevy Chevelle Laguna Type S-3 350 small block engine bay

A: If you are certain that you did not nick a cam bearing, then the only other thing we can think of is that there is a clearance problem between the bearings and the cam. It won’t be easy to do, but you will need to measure the outside diameter of each cam journal and the inside diameter of each cam bearing and make sure there is enough clearance. We would also check the lifters to make sure they are not binding up in the bores.

This is another in a series of weekly Q&A Mailbag sessions with Summit Racing‘s tech department, in which there are hundreds more. Click here to see them all

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Author: David Fuller

David Fuller is OnAllCylinders' managing editor. During his 20-year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In 2012, he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.