I'm running this same cam and using the LS6 springs. The 02' and up LS6 had over .550 lift and LPE sells the LS6 springs with their GT2-3 cam which is over .570 lift. My gas milage is just fine. I'm anxious to get to the track now myself. The low rpm torque is better than most would guess.

 

pushrods are now .070" shorter

notice loss of tq below 2200

I have run up to 6800 a few times. With these gears the 1-2 shift breaks both tires loose at 85km/h. No 1/4 mile times or video yet

 

I was running that camshaft in my 5.3L and it did a heck of a job with full bolt-ons good tune I went mid 12s

 

Do anyone know what the base circle of the XR275 HR and the base circle of the LS6 cam is. I Installed the XR275 HR a couple of weeks a go had a LS6 cam with LS6 heads milled .050 and GMPP .053 headgasket and crane gold race rocker kit. The vavle train was a little noisy but not to bad couldnt real hear it driving but in a drive through or somthing next to the truck you could hear it echoing back. Now with LS7 lifters and the XR275HR and .053 this thing is bad noisy. The crane push rod are 7.250 every body says measure with a pushrod measureing tool but thinking about it the rockers are adjustable so if you stick the tool in there and turn the rocker adjuster to zero lash that would be 6.800 plus .080 for lifter preload or .086 for two complete turns like in the crane directions would be 6.880 or 6.886 which I dont think is right. Not like nonadj. ones that you would torque down and wind the tool out to zero lash and add .080 to. So I think if I know the diffrences in the bace Circles maybe I or someone can figure it out what length I need just from the measurments.

 

In the "tech" part of the Comp Cam website they recomend .030" lifter preload with roller lifters. The tech/sales tollfree phone number guys are helpfull too

 

Just dyno'd mine. Results in the dyno section.

 

Zippy,are running factory exhaust manifolds?
your graph looks very even tq/hp numbers, I feel thats about the same as mine
very flat tq curve
long tubes to install next spring

 

I think you will gain bigtime with headers. I've come to the conclusion that the stock exhaust is GARBAGE...the manifolds, the muffler it all sucks.

 

Yes, I'm still running manifolds. I plan to go long tubes in the spring if all works out as planned.

 

That cam did wonders on my fully bolt-on 5.3L and a good well built transmision 3400 stall and 3.73 gears and a well tune ecu you will see good results i went mid 12s on that bump stick...............good luck