My point stands that I pushed 477hp thru the entirely stock system. Muffler, cats and stock manifolds included

Its very well documented that these engines pick up ~40hp from LTs and associated tuning changes

Shouldn't be any confusion there, unless you're into the business of forging/plagiarizing dyno graphs @Fast355

 

I have shorty headers and would it be a meaning full upgrade to long tube?
what so bad about the ported throttle body from projet?
Looking into some heads now what's some good options, cant up compression without going e85 already running 91 on vp madditve

 

The confusion comes from a green horn like the original poster reading between the lines of your post thinking that headers would not be as beneficial as they actually are

 

What is your current compression ratio? Are you saying you can't add more because of timing?

Def do LTs. Shorties are considered to make the same power/flow the same as the stock manifolds

Ported TB is just a great way to waste money. GM used the same 78mm TB on the 405hp LS6. Those larger engines at higher RPM pick up like 7hp from a ported TB at 6500rpm. Your 5.3 won't see anything from it, but your wallet will be lighter

Move from a 78 to an 87mm for any real/appreciable gains

 

you the benefits of long tube headers versus shorty headers is approximately the same as the benefits of long tube headers versus stock manifolds. Approximately 25 to 30 horsepower, especially right where you need it most in the mid-range. The reason to not buy a ported throttle body is tuning difficulties and erratic off idle transitions.

 

You beat me to it, MacArthur

 

yes timing is correct doesn't adding compression also command for better fuel

 

You motor is 9.5:1

The LS2 is 10.9:1 and rated for 200k service life on 91 octane, You can add a lot more compression and be totally fine

 

For starters state your budget and your goals for this build.

 

This^^^^