I have a 2001 silverado with a 2002 5.3 and would like to know the stock camshaft base circle, is it 1.49 inches? Can someone please take the time and measure the base circle of there stock 5.3 cam if they have one laying around? Thanks!

 

1.49 inches is dead on buddy...just looked at my stock cam out of my 02 5.3l lm7 motor and put the tape measure to it and base circle was almost 1.5 to my eye but just shy. Sorry i can only be but so accurate with a tape measure and naked eye haha, hope this helps!

 

Thanks for measuring. I never measured my stock cam base circle before I sold it last year after the ZO6 cam swap. Now I am installing a lunati cam and the base circle of the lunati cam is 1.49 and I just noticed the base circle of the ZO6 cam I installed last year is 1.52. I just want to make sure I buy the right size pushrods. Does anyone know how to measure for preload? I was told to make sure I had approx .040 - .060 preload after I tighten down the rocker arms. Thanks again for your help.

 

Alot of the threads I've been reading lately guy's have been recommending .06 to .09 for preload in order to have a quieter valve train. Search a few threads for lifter preload in the GM Performance section, or the Internal engine mods section.