Ok, i have a basically stock 2003 5.3 in my truck, currently has 66K miles, and i have a set of Pacesetter LT's and ORY that im going to install, the truck already has efans and rad from a 2007 and a nelson harness. Im going to be installing the headers in the next few weeks.

I have a cam that is very close to a stock LS6, its 218/218 .563/.563 on a 117 that i wanted to install also, but i was wondering, if i dont change the way i drive, and all else being the same will this cam cause my MPG to take a major dive or is there any chance of my MPG going up?

 

18 mpg on the highway before I swapped to a six speed, I'm up to 20mpg now

 

I don't think MPG will get any worse by the camshaft, I think it'll get worse because of your new-found power. But like you said, if nothing changes, you could probably count on an increase in mileage actually because any cam requires a tune after, and your tuner (or yourself if you tune) will be able to optimize the motor around the cam to run at it's efficiency level for best MPG.

 

+1...

 

Digging up an old thread, but are the stock 24.x 5.3 injectors enough for your combo?

 

Should be close... I think I was at 108% IDC with the tsp 220 cam shifting at 6500 rpms. Might as well go ahead and swap to some bigger ones.

 

6.0 in my s10 with ls6 cam is knocking down 23-25 with light throttle.

 

Put the Z06 cam in my 5.3 swapped Porsche and did not loose MPG's (AVG 30). I DID NOT even re-tune it afterwards. The Upper RPM's pull much harder now even with the taller 5th gear I swapped in.

 

Got a build thread any were??? I would like to see an LS into a Porsche swap.
I know they have been done before but still like to see what people are doing with them.

 

I'm working on a GM 3.8 swap kit this winter too......
I have literally tried to destroy this motor.....still keeps humming along at 6500 daily lol

nailed it - Nailed it.....Xschop's 5.3 LM7 build