denali_on_26's

iTrader: (26)

i have a 2005 crew cab with LQ4 and 4.10 gears and 26" wheels (33.2" tall)
the truck is stock other than 05 electric fans, K&N drop in, RWTDtune, catless and a magnaflow

I am thinking about pulling the 6.0l out and sticking a 5.3L in its place..
i would like better fuel economy out of the truck WITH OUT TAKING THE WHEELS OFF..

here are my options with a 5.3l:
stock 5.3l
5.3l with 706 heads milled .025, 3 angle valve job, and stock 317 valves
5.3l with stock heads milled to the max (.040?)

what do you think?
how do you thing the 3 setups would compare VS the lq4 hp/tq/mpg?

i don't "NEED" the power that the lq4 has but its always nice to have it but its not worth the money i have to spend every week driving back and forth to work..
fuel economy is (i drive very reasonable) and all MPGs are according to the dash display but are VERY close to actual calculation
town 12.8
highway 16.7
average 14.0

LsF-150

iTrader: (2)

Maybe consider a gear change? I just went on a 600mi round trip in my 06 crew cab with 22's (31.5 tall tire) and got 19.0 all highway, all 82mph, ac was never off and had luggage...lq4 with tsp 5.3 heads, small cam and headers with a catted y-pipe and stock catback. My truck has 3.23's at 82mph I was just a scosche over 2000rpm's. I also have the entire truck sound deadened, amps, subs, 150lb fiberglass tonneau...its heavy and its never been tuned (been too hot) I just have lq9 spark and ve tables loaded into my stock 5.3 tune. It doesnt knock, runs 12.8 in pe and 14.7ish everywhere else...btw my in town mileage is almost exactly the same as yours, low to mid 12's, my dic is also spot on everytime I've manually calculated it...

726.0chevelle

iTrader: (17)

A gear change might help you out I have a 99 ecsb 5.3L with denali 20s with 285/55/20 tires 3.42 gears and the only time i tested the mpgs was on a road trip with 3 people in the truck plus a bunch of luggage i got 19 on the highway cruising between 65 and 70. As far as bolt ons my truck was nearly 100% stock. The reason why I say a gear change is now I have an lq4 and comp 265 and I havent tested the milage but just driving normal i cant tell any mileage change.

iamkeniff

iTrader: (16)

the more hp/tq you have the less the truck will struggle to move. make everything under 50% throttle more fuel mileage concerned and anything over 50% extreme.

i get 4mpg when im wot and headed to 120mph lol

denali_on_26's

iTrader: (26)

I went from 3.42 to 4.10 and picked up 0.6mpg on highway and 1.6mpg around town and 2.5mpg towing
So I think the gears I have now are in a good hp/tq vs weight @rpm

budhayes3

iTrader: (19)

I'd think that the 5.3 would have to work so much harder than the LQ4 to get that heavy azz rig moving that it would negate any mpg gains, if not get poorer mpg...just guessing though...

iamkeniff

iTrader: (16)

exactly....thats i think the 6.0 with a torque style cam would be better imho, but im guessing at it too