if i remember correctly they have 1 5/8" primaries. from what i hear they are good for stock or close to stock apps. make sure you get them coated though, ive heard of a few sets where the primaries completely rusted through on uncoated sets.

 

I think Hooker makes shorty's for Gen III trucks but not sure.
Having just shed the shortys for long tubes I cant say I lost any bottom end at all, as matter of fact it feels better on the low but then again I'm pumping a bit more air
I agree that for shorty's don't give that much bang for the buck but they are better than the stock manifolds, and I just happen to have a set of JBA's for sale

 

Hooker makes a true LT for 99+ trucks. In 2 different primary sizes to boot.

But either way. Long tube or nothing.

 

Longtubes increase low end torque by scavenging more air into the collectors. This has been proven many times over many years.

 

Yes I agree, but at the same time, he has no need for 1 3/4 primaries. It's the same as running a cutout. Stock people aren't going to benefit from it, but modified truck are going to see gains.

 

Thanks for the info. Does Thorley have a website. I can't find it. Anyone have any clearance issues with thier headers? ex: spark plug wires, steering, oil dip stick, or anything like that. I've read a lot of posts and all the ones I read about needed some kind of modifications.

 

Looks like Thorley's website is under construction.

As far as installation problems go, most that I have read about happen on the 4X4s with LTs. 2wds are pretty straightforward. I know that TooTall put some Pacesetter LTs on his Silverado (I believe it's an '02) without any clearance issues.

Now once you get the headers on, you have to hook up the muffler. If you want to keep your cats you will need a custom Y-pipe fabricated. If you eliminate the cats, you can get an off road Y-pipe from the header supplier, which will mate up to the muffler with some minor welding.

 

4x4 w/LT's here and the only modification is trimming the wire boots to slide on further so they don't burn.

There's truth to what Mark's saying too but if you use a Y-pipe and don't supersize your exhaust diameter, it'll gain torque and not rob power. Think of it like a HVAC system; start at the source with larger duct and reduce it to maintain power as it extends away.

 

Not a single problem with clearance, wire burning, denting/bending primaries, nothing.

 

Hey 99Silver6.0,
How's your set up Corsa & Dynatech? Sound and performace? Do you have any pictures of your headers on your 6.0 and/or any sound clips of your exhaust system. I think I'm going with the route you went with, but I would like to hear what it sounds like.