alright my dads got a 5.3 NNBS 4x4 crew cab w/ 33" tires, my mom uses it as her daily driver (she drives bout 10 miles and parks it all day and my dads an area manager that puts 50-100 miles a day)...
its has HPtuners, CAI, and cat-back...
well my dad want some extra torque for when he gets in it on weekends, and towing...
i don't want to put a set of pacesetters on the truck since it rarely sees above 3500 rpms where they shine (like i said its my moms daily)...
thorleys seem to work great 1500-3500...
has anyone used these on a NNBS???, my dad cant afford to have the truck down for more than a day...
The truck WILL retain stock cats and converter...
EDIT:
i know i will have to make a custom y-pipe, thats not an issue...

 

has the hptuners been used?.... I was going to suggest a tune.

smallish cam possible?

headers really wont do a whole lot for you in that range, especially since everything else is stock.

 

ya the same guy that has my truck tuned did his...

well truck has a 5yr/100k drivetrain warranty..
so touching the motor is out of the question, as are gears since they take trips with it..

i would think this would be the next bolt-on besides a pulley???

 

Next and most effecient may not be the same thing. Since the rest of the exhaust cant be changed, headers arent going to do you a whole lot of good. A small stall like the traileblazer stall would make a big difference and still look factory...

 

i get what ur saying atomic, but for future reference i would like to know will these headers fit a NNBS 4x4..
i know pacesetter makes a set for NNBS, but im lookin more for down low not high rpm like mine has turned into...

 

bump...

 

ttt....

 

Man, I don't know if they fit on a NNBS but when I got them a year ago they come with a packing slip from Thorley that says: "Header, tri-y, GM, 1999-2008, 4.8-6.2, Pick up, 2/4WD (Legal for 99-01 only)."

Part # THY-310Y-C

I'm reading it as we type so it looks like they fit, hope it helps.

 

bad *** man, thanks..

 

I'd give Thorley a call to be 100% sure.

And in case you don't know, you need to order headers for 99-01 trucks if you want LT's. '02 and newer are shortys.

The part number I posted above is for ceramic headers.