i need help on deciding which push rods to go with. i am putting my shaved 5.3 heads on my 6.0. they are shaved 35 thousandths. i'm using the gm steel gaskets. my cam is a futral f4 cam 226"/226" .575"/.575" 114LSA

i have hardened 7.4" pushrods and hardened 7.350" pushrods. not sure which ones to use. i'm not a math whiz nor do i know the formulas that you smart fellas know.

 

If your heads are flat milled then the pushrods would need to be .035" shorter optimum. The key is about the base circle of your cam. It is probably .050" smaller due to the lift. The larger lift won't fit through the brg journals if you have the same base circle. This is only the case with gen3 engines but nevermind that i'm just rambling. My guess would be the 7.350 rods should be just about perfect. May have to go with a 7.325-7.300 depending on the cam base circle. Maybe some guys with futral cams will post up or you can call them and see. The hydraulic lifter will take up a good bit of error (slack), probably up to .050".

 

cool. i'll throw the 7.350" rods in there and try it out. these rods did not like the 5.3 with the same heads. too much damn noise. then again, it might have been right on and the noise is something i am gonng have to live with.

 

Since you had problems before i'd call futral and get their recommendation with their can and the milled heads to save you some time and headache.

 

i emailed allen@futral to ask about the pushrods and base circle, with my FMS F5 cam below, he said the base circle was the same size and the pushrods should be 7.40" but since you milled your heads i dunno what to say

 

You can get a pushrod length checker for like 12 bucks if I remember correctly...I bought one a while back from Thunder Racing (I think...maybe SDPC? can't remember, but it was one of our sponsors...anyway...). If you check out Vinci or Comp's websites, there should be some "" and FAQ sections that outline the proper way to check pushrod length. I actually think that someone posted a link to the info a while back. This way, if you use the right tool and figure it out properly, you know you've made the right choice first time out without the trial and error.

 

Like howard was saying the lifters can take up a huge amount of slack Ive heard .100
I took .050 off my heads with an aftermarket cam and at first had 7.35 they were too noisey so I put the stock 7.4 in and it quited it down alot. Plus later on I added about 3lbs of tq to the rocker bolts to make them 25ft/lsb and that helped slightly plus it feels tighter. I know its a backwoods method of doing it and normally I dont like doing things that way but its worked well for over 23k miles this way. Hydraulic lifters have thier benefits.

 

i'll make some phone calls to be sure i am using the right length with that cam. thanks fellas.