pushrod length question/adjusting valve train preload
 

I just recieved my B303 cam and i'm going to be putting it on my 302 with my 1.7:1 Cobra roller rockers and GT40 heads.

I was wondering, will i have to change pushrod length or put shims underneath the pedestal mount rocker arms. I read in a ford manual that you use shims after milling the heads (or get shorter pushrods) and i've heard people put different length pushrods with different cams, but i'm not sure what i need to do in my case.

I'll have a total of .510" lift and i'm using new Ford hydraulic roller lifters.

I appreciate any input, thanks,

Rick

You just need the standard 7.6" pushrods. The rockers should have come with shims, just in case you need them.

FYI. . . I installed an F303 last year with Ford Racing's roller rockers and didn't have to use any of the shims and havent' had any problems with it yet.

You may have to use shims based on the travel of the rocker arm across the valve stem. If the B303 has a smaller base circle than the stock cam, you may have to use a different length pushrod also. The best way to find out is to assemble it (correctly), and then turn the engine over by hand and watch the path of the rocker across the valve. You want as little movement as possible across the valve. It sounds tedious but if you do it right the first time, you won't have problems.

awesome, thanks guys! I have no problem spending extra time making sure it's correct, i'd rather do it right the first time than to screw around and break stuff.