For one reason most all the backpressure is from the turbo itself, so headers won't help there. They also create more heat loss than manifolds. So the trade off usually isnt worth the $$$, or better spend elsewhere.
BTW: We have installed this system on both LT1s and LS1s with and without headers, and the manifold cars haven't had a problem putting the power down.

 

I can't remember the specifics but since there is much more back pressure in the exhaust system between the heads and the turbo the scavenging affect of the headers doesn't really come into play. Maybe someone will chime in with actual knowledge. Also stock manifolds are said to reatin heat better. *shrug*

 

This is interesting to me because I eventually want a turbo system but I'm also interested in the Kooks LT1 1 3/4"-1 7/8" long tube headers. Please keep this thread going.
FLeX

 

This is troubling for me to hear, as I'm in the middle of my coated SLP shorties install.

I guess I should be happy that I got them used, then.

 

Shorties suck anyway so no biggy mate

Since they are smog legal just keep em on.

 

So would getting headers be a good idea just for the plug access then? I've never changed my plugs and wires myself but I heard that they are a nightmare on stock manifolds. Maybe even just some cheap shorties will do if I can find some that have good plug access.

 

Im torn because under normal driving the headers have to be helping with normal cruise and power. I have headers now but also have manifolds I can get jet hotted with a bassani y pipe built for stock manifolds. Anyone know the HP loss between the two on an sts car

 

There is not a significant difference either way. IMO, it is not worth it to spend the $ on headers if you dont already have them. If you have them, great, keep 'em. If you have LT's, it will save you a few minutes on the install since the drivers side cat is close to an area where you have to work.

 

A pro for headers is def plug access, but a con would be leaking. Make sure its a quality header and keep a good torque on the bolts (or locking bolts), because if they are prone to leaking before they will def leak with the exhaust pressure from the turbo system.