A question I have seen asked several times, and one that also interests me, is if I install different rockers will I have clearance issues with my valve covers. Well I just had my stock valve covers off on my 1989 5.0 liter engine. I measured from the raised perimeter lip of the head to the highest point of the rocker and got a measurement of 1 5/8”. Then I measured from the corresponding perimeter lip of the valve cover to the ceiling of the valve cover and found they were 2 1/8” deep. So we have about 1/2” clearance to play with for after market rocker arms.

 

Contrary to popular belief you can run pretty much any stud mount rocker arms. You will need to trim the inside of the covers.....some more than others depending on which rockers. I myself like the Comp Pro-Magnums. Good luck!