I ask them if they will bolt up to a stock exhaust and they said it would.

For you guys who have done it, is this true? In other words do you have to do any cutting or welding?

 

You really aren't going to "feel" any difference between any longtube header and the other IMHO. You may or may not see a couple horsepower difference between one or the other (on a chassis dyno), solely because your combo/engine is better suited to one or the other, but your "butt dyno" will be VERY hard pressed to feel any difference, except of course, in cash outlay, since the Ebay headers/y pipe combo are a good bit cheaper than any offering from Pacesetter. If you absolutely believe that you "need" 1-3/4" headers (with a simple bolt-on 4.8/5.3 truck), as opposed to the 1-5/8" Ebays, than the Pacesetters are for you. If you want a stainless header/y pipe combo that will work absolutely fine in an UN-cammed, basic bolt-on 4.8/5.3 truck, then spend the $300 and be happy.

ABSOLUTELY NO MODIFYING/WELDING/CUTTING/BENDING/ETC. to get these to bolt to a stock, or stock style catback...

Tons of tips and info for you right here:
https://www.performancetrucks.net/fo...d.php?t=450962

 

rel3rd is right. the only way you might be able to see a difference is by putting the truck on the dyno. Even on that, it all varies with your exhaust set up and so on. You cant just bolt them up and expect to feel a difference in hp just because its a different brand. Although you may be able to feel a slight difference from stock to aftermarket or shorties to long tubes. just my two cents.

 

I think I should have been a little more clear, I have to keep my stock cats, so from the cats forward will they just bolt up?

 

they bolt up directly to your stock cat-back. you cannot keep your stock y-pipe with these, but if you read the link rel3rd posted i think somebody said the resonators act just like cats

 

no it wont bolt up. if thats the case then maybe you should find a set of shorties instead of longtubes. But you should be good to go with the long tubes considering it comes with resonators that replace the cats. Also replaces the stock y-pipe