I need to get more exhaust flow for my new 408/TVS1900 combo. I definitely left some power on the dyno where we ran 1 7/8 long tube headers. Is there any consensus on the best headers for FI? I have an 03 Denali and will probably switch to a true double exhaust instead of the y setup. I have done a little research on the forum but haven't scene anything specific to FI. Thanks

 

the only 1 7/8" primary tube headers I know of are ARH... no 2" that I know of, but some have success running Kooks 2" f-body headers on their trucks.. I think the concensus is the Magnaflow spun metalic cats flow best.

 

I can probably live with 1 3/4" primaries with a 3" collector but the dyno was 727 hp so I might lose a little. My research indicated only two high flow cats, the magnaflow and random tech. Anyone else?

 

I don't know whether or not it has ever been brought up as to if the ARH headers were designed to fit a 4WD/AWD, but from what I've heard the Kook's F-Body header's won't. So at least the Kook's are out for the Denali.

 

LPP Drivers Side
Looks like the LPP's will fit if 1 3/4 is good enough, it's what I'm going with, but you will have to fab you mid pipes if you want to stay with the dual pipes like factory. LPP only makes the Y-version like a 5.3 truck

 

Is this for a full size truck?? check into kooks f body headers, have heard that they fit pretty damn good, but have no first hand exp with them. Also like stated ARH is a option if you must have bigger then 1 3/4 primes

 

I have the american racing headers and fitment was perfect and build quality was as good as I've seen. Can't go wrong with them. They will make them to what ever specs you need, great guys to work with.

 

Moregrip put together a spectacular build a couple of years ago but it looks like he was still throwing some codes while cruising. Here is the link to his setup. https://www.performancetrucks.net/fo...d.php?t=359975

My machine shop should be able to duplicate. I appreciate the suggestions, I will call around and see what kind of prices are available. I like to idea of a quiet setup until you get on it so I may go with the 3 muffler design like grippy. Anyone here used the Random tech cats?

 

Hey man. Only one brand you can use. Dynateck for the 8,1 L setup. I run this setup with a Corsa exhaust on a supercharged 408 Ls1 Stroker with a P1-SC modifyed procharger in a 2004 Chevy tahoe. It handle my 800 hp.
Reg Chris.

 

if choosing between equal sized kooks and american racing I'll cast my vote for american racing, I have 1 7/8ths from both companies on both of my vettes......the ease of fitment and quality is better on the american racing, and given same car same day same dyno I've seen better results with them first hand.