how much of a gain would i get from dynatech longtubes with cats, right now i have a 5.3 just a cai, tune, and magnaflow exhaust, is it worth it and would i lose any low end?

 

its very worth it. I'd recommend pacesetters if you dont want to spend alot of money on headers, although theyre very nice headers.

however I am running no cats now, so I'm not sure how different the power gains would be, but i gained power throughout the entire powerband, especially low end. Before, my 4th gear felt like it had no *****, and was always bogging down. now it feels alot more powerful and doesnt need to downshift as much

 

yea they will make a difference for sure!

 

probably the best bolt on you can buy. also recommend pacesetter lt, great header. i think i picked up a little power down low.

 

I had a 5.3 Avalanche with a FIPK, tune, and cat-back, with Gibson headers. I had no noticeable gains with installing headers. That also could be because I did not have an after market Y-pipe, and in 5.3s the Y-pipe is crimped, so that will restrict flow. I do not recommend getting headers alone, and I have looked into Dynatech and they look impressive.

 

gibson shortys?
that was your problem right there.
go long or go home

 

gibson shortys don't flow any better than stock manifolds, longer is better. i almost got as much gains out of the headers and exhaust than cam.

 

a custom tune or retune after LT headers is practically a must!

 

I think the 1.75 headers are too big for the 4.8/5.3...depending on your plans and your exhaust. I've got the 3" Magnaflow single in/out with a 3" exit pipe in the stock location and I felt that I lost some low-end after the headers. I also have to say that I think my tune really needs some adjustment and that'd definitely make a difference.

 

so if i would get the lt's i would have to get a retune ? i have a tune from allen nelson right now