Hi, I'm putting a 224/224,588/588,114 cam and ls6 243 heads on my 99 ls1. which length pushrods do i use? 7.4 or 7.425? Please help! Need to know fast for cam and head swap

 

It should be the 7.4s but the only way to know for sure is to measure. Get a pushrod length checker, that's one of the easiest ways.

 

7.400!

 

Most 224 cams are in the 7.400 area with stock style heads, vavle angle etc.

Best to look around for a dial indicator with vice grip base?

Find a cylinder that is on compression or vavle that has no lift acting on it.

Install a 7.400 PR; tighten the rocker arm down till it has no play no preload (zero lash) zero the dial indicator and tighten down the rocker as you would normally, when tight the number you obtain should be .040"-.080".

If the number isn't .040"-.080" you will need corresponding length pushrods to obtain the ideal preload number.

 

i read stock preload was .080-.100 ?

 

.090 is the magic number.

 

You need to take into cosideration you will have a thermal expansion of .030"

I like to be at .060" preload.

 

.060 cold ?

 

Im guessing those are XER lobes. If so I ran that cam with 7.400 and it was noisy as hell. Id go with the 7.425.