well as of last night my head gasket went on my silverado, luckily it was an external leak not internal,theres no coolant in the oil but either way the topend has got to come off...i figured while i was in there i might as well freshen the heads up, get them milled and might as well swap a cam in too. although i was gonna go custom ground right now i cant afford it so ill be purchasing a cam package through tsp. my question is if i have the heads milled .030 and run a .040 thickness instead of the .51 headgasket what length pushrod should i run? and also what would my CR be around? ive heard of intake mani fitment issues with anything more than .40 being taken off so id like to keep it in a safe ballpark lol. if anyone could help me with the desired pushrod length and CR itd be greatley apprciated!!

thanks for your time

tj

 

with that I would recommend getting a pushrod length checker and measure lifter preload.

 

i was hoping it wouldnt have to come to that lol...i mean thats the best way to do it but this is the only form of transportation i have, if i gotta buy a checker then measure then order pushrods its more time the trucks down

 

That or buy pushrod tool and also buy multiple sizes buy stock length and do you math and buy ones that are by your calculations more expensive but if you don't have the time that's really only way I would see how to do it

 

thanks also for the advice man i appreciate it. when i call tsp to order the gasket kit and cam kit ill see what they say, youd think theyd have someone thats had some sort of similar build so mabey theyd know? if not i guess im just gonna have to go with one of those routes

 

I'm running 243 heads milled .030 with a .040 gasket. I'm using 7.350 pushrods with LS7 lifters. I have no idea what your compression ratio will be off the top of my head, but something tells me you'll want to start running a minimum of 91 octane without a retune.

 

i take it id probably need right around a 7.3 since the ls7 lifters are a little higher than the small bore ls1's, the only thing im worried about is PTV clearance, idk if itll be an issue with around a 226-228 duration cam, and thats fine with me im already stuck on a 93 tune so im kinda used to havin to spend dough when i fill up lol

 

Duration has almost nothing to do with PTV cleareance, fyi.

 

i know its the lift that determines it but tsp classifies their cams by their duration tsp 224 228etc...

 

Not even the lift...its the timing of when the valves open. The cam designers try to take this into account with lobe shape, which is why you rarely have problems on stock-ish setups. But when you start shaving heads and used different gaskets, the potential to run into problems is there.