The heads I run have stock chambers, I want to raise my compression ratio to 11:1 how much would I have to shave the heads, what size would the combustion chamber be. I need to change lifters, what GM lifter would work best on a 5.3. I'm going with a bigger split pattern cam. Comp suggested a XER 281 HR part#XE R54446-11, it's 232/234* dur. .595/.598 lift 112 lobe center angle 2400-7200 RPM range. The heads flow 290cfm @ .600 lift, the exh flow 216cfm @ .600 lift. I'm also gonna add a LSXrt Intake manifold and 102 mm Throttle body. What would be the best valve spring to run with this setup. I'm running Patriot Gold duals now. Thanks for all the thoughts, opinions, criticism and knowledge.

 

that cam is awfully big for a 5.3even tho you have heads

 

The cam in it now is 226/226 .585/.585 112 LSA and it handles it real well.

 

any track times with current setup?

 

After seeing Phantom's (Dozerdan) setup, I'd say it would run good if you had the supporting mods. 4000+ rpm stall and 4.56 gears, but he was in a RCSB not a EC.

 

honestly i don't think you can get to 11.0 CR... I think the most you could get is 10.5 milling them to 56cc and .04 head gasket...

 

You would need to use .035 thick head gaskets and shave the heads .050 to get 11.00:1

 

Best time is 13.686 @ 98.02mph

 

damn and you got more head,gear and stall than me
I have been 13.8@100 with a 2.0 60ft on my setup

 

That's with street tires I tried some drag radials, but they weren't big enuff, I need to get a better tune also, but I have the intake and needed to change the lifters so that's why the extra mods, also I'm sure the heads would breathe better with the split pattern cam. I also had some valvetrain instability in the past.