LS1 pwrd NOVA

iTrader: (1)

This is just my daily driver, all stock & no racing and barely tow anything.
My truck has a 60e, 3.42 gears & 265/70/17 tires.
My 4.8 has 180k miles and so does the Lq4.
My truck gets around 14 city and maybe 16 hwy, this is crappy fuel economy to me or maybe the 4.8 just sux in heavier vehicles.

So I am thinking to swap in the lq4 and leaving it stock as I'd rather have all the low end torque from it and whatever power I get on top is a plus in stock form.
Now what do any of you all think about that?
What kind of mpg will I get with the 6.0 in this truck or has anyone done this swap?
I'm hoping I don't lose much or get the close to the same mpg.
I do know I'll love the power increase no matter what.
I also have a set of gm 3.73s to swap in with a stock posi or keep the 3.42?
Also should I get the exhaust off of the donor truck as I think it is bigger than my stock 4.8 exhaust.
Should I hollow out the cats for more performance or will it just hurt my low end torque and mpg?
Will headers make any low end grunt difference and any mpg gain?

madmann26

iTrader: (7)

The 4.8 sucks in a heavy vehicle unless you are boosted or something.

The 6.0/3.73 swap would be worthwhile but I'm afraid you're fuel mileage may only get marginally better, if any.

TrendSetter

my rcsb with mildly hot rodded 4.8 and 373s gets about the same mileage and its a turd out of boost. If i didnt have turbos on it i would definitely want more inches.
I dont have any experience with 6.0s, but its probably worth the swap if you can do it yourself

2002_Z28_Six_Speed

iTrader: (20)

I get about 12/16 in my modded LQ4. Was about the same stock.

Wolftrk99

iTrader: (5)

6.0 swap would be worth it, yes to gears and posi, as far as exhaust what set up does the donor have??? Ypipe or separate cat pipes?? If separate cat pipes get those and manifolds..... If youre gonna gut cats make sure you get it tuned.... Properly working cats really make no significant differemce in stock pipes...

GMCtrk

iTrader: (27)

A Stock 6.0 is a still turd.

Headers won't make any difference down low.

Wolftrk99

iTrader: (5)

Anything stock is a turd... But 6.0 is a helluva lot better than a 4.8...

LS1 pwrd NOVA

iTrader: (1)

Madman, if I get equal or even 1 mpg more I'll be happy.

Trendsetter, I'd like to go turbo in this 4.8 but I don't think it's worth it price wise as my 69 Camaro needs its turbo setup first. I'll do the swap myself also as it's not hard.

2002z6, that's good to know makes me know mpg will be the same.

Wolfrrk99, I think it's separate pipes around 2.5 or 3" with separate cats if I recall. good to know about the cats. I have Hp tuners and well slowly tune this truck up over time.

Gmctrk, I kinda knew it'll still be slow but I'm not going to race it. What will headers do, just move my peak numbers up higher in the rpm band?