I have the LSX-LS7 gmpp heads ti intake sd ex on a 427 LSX boosted never ran yet so not sure on boost psi, as im wanting diff springs than the ones the heads come with, pockets are big enough for 1.55" what would be the best spring for this combo be, cam is a TS ls7 grind .656" lift
hyd caddy lifters if i remember
F1 procharger 15-18 psi

 

I wonder how will the sodium filled exhaust valves will hold up?

 

What rpm range are you shooting for? Anything over 7500 I would suggest going to either a solid lifter or low pump hydraulic that can handle over 500lbs of pressure.

As of now i would suggest either the pac 1294 or the pac 1371.

 

I think I will replace them with manley extreme SS

 

7000 7200 whats a low pump hydraulic ? who makes them ?

 

added a couple pics

 

Morel makes them. They have a shorter stiffer spring so they will not bleed down like a street lifter. A little more money but it would be worth it for you to be able to run higher pressures.

I brain fart a few hundred times a day and can't remember the correct term but someone will chime in and correct me.

 

i know how you feel on the brain farts lol

thanks man

 

From the photos it appears that the spring retainers are a different distance from the valve stem tips on the intakes vs exhausts??

 

yes the intakes are titanium so the lash cap is off they are same length inst hieght

what rockers are you using ?

gona get the t&d shaft rocker set i think

 

Crower stainless shaft mounts.

 

are those ls7 offset ?
whats the cost on those ? i didnt even know crower was making any ls7 rockers

 

LS7-ETP $1284 on their site. Not sure about anything for the GM heads.

 

Crower is the way to go! I bet 95% of the people on here don’t know they exist. Personally, I would never go back to an aluminum rocker but that’s just me.

 

I see crower has them now pn 74107 for stock ls7 which is what the LSX LS7 heads use "nice"

 

They are very, very nice. There is not as much weight over the valve stem as you would think for a steel rocker, yet they as close to indestructible as you can get.

 

i ordered a set of the crowers they are nice didn't know they made for the LS7, i always have been a fan of the SS rocker as they are way stronger , last longer almost forever, and i bet they weigh less over the valve