im just curious but a friend installed a 216/224 114 cam i believe in his 01 5.3. He said someone told him to put 7.3 pushrods in instead of the 7.4's to make the valvetrain geometry correct? I thought if anything he would need longer rods since the cam base circle is smaller?

heads and everything else is stock btw.. just a cam/spring/pushrod swap.

if he did put the 7.3's in, what side affects would he cause compared to the 7.4's?

 

i don't know about the 7.3's. when i did my cam swap all i did was change the springs and pushrods. went with the manley chrome moly pushrods 7.4's stock length and torqued the rockers down to 22ftlbs.

 

7.3 sounds too short to me, I agree that with the smaller cam base circle, he'd want to go slightly longer if anything. Comp recommended their 7.4's for my 206/212 cam, and I know in my heart that if I got a pushrod length checker I could probably go a little longer and quiet down my valvetrain some. You'd think that too short a pushrod would allow for excessive vavletrain clearance...I'd bet that the lifters would be jumping off the cam lobes.

 

i used some 7.4s with mine, i've heard of some guys using 7.35s but not 7.3s

btw i have a set of thunder racing 7.4s for sale if your intrested

 

thanks for the info everyone.... he found out that he needed 7.4's instead so all is good to go now

 

for proper preload he is gonna need a hair longer than 7.4, what is the difference in the base circle between the aftermarket cam and the stock one? Account for the difference with a longer pushrod, it will sound like a tiny diesel with the stock rod size if he has allready done it youll hear what Im talking about.

 

Not 7.3 thats way too short. Pushrod length on a 5.3 with an AM cam should realistically be 7.425 or 7.43.