Alco

I use to own an Avalanche 2500 8.1L and loved the truck so I'm thinking of selling my lowered '02 RCSB RWD lm7 1500 to go for a ECSB 4x4 LQ4 2500HD. I love my RCSB and the power is decent for a little truck but I can't bring the wife and kids for a ride and with the harsh winter ( and sketchy driveway) the truck stays inside all winter and use my Subaru!

I like the looks of a HD, need the 4x4 and the towing capacity ( Race car hauler), the 4L80E and 14 bolt is an added bonus !
Will a Gas 6.0L 2500hd be a big turd ?
Will a LSA blower and LS3/L92 heads do any good to the truck?
What about gas millage with the blower ?
Any weak point to look for ( that are different than the 1500 I already have)?

Any good advice is appreciated !

GMCtrk

iTrader: (27)

Given that you already had the 8.1, I'd try and find another 8.1 vehicle. The 6.0 will probably be underwhelming in comparison and everyone I've seen on here that tries to mod a 6.0 HD for towing ends up regretting it.

Wolfe Performance

Having had both, I can attest to the fact that overall you will probably miss the 8.1 for towing. I had an 01 2500HD with 8.1/Alli combo, and only now that my 07.5 with a 6.0 has a S/C running 9psi through an LSA is it comparable.

The transmission is a huge consideration as well. If you take a 6.0 in the 99-06 range and put an S/C on it, you'll be close in power but still have an inferior transmission. The 6 speed in the newer body style has been great... don't really miss the Allison with this one.

Not to mention, the MPG out of an 8.1 was surprisingly good - better when towing than my S/C'd 6.0.

Wolftrk99

iTrader: (5)

The 8.1 avalnches got ridiculously good fuel mileage.... I had one and kick myself everytime i see another avi.... Went to an 8.1 dually with an allison and 4.56 and about killed myself trying to pay for the truck and the fuel, would pull anything in 4lo, but mpg was not worth it....

zraffz

iTrader: (1)

I like my 2005 2500HD (6.0 4L80E 4WD 4.10 gears) SCLB. It gets 12 mpg local driving. I bought it to pull a small landscape trailer and 48" bobcat zero turn mower to mow a few lawns after work.

I plan on using it to tow my street/strip S10 to the track. I've towed with a few 6 liter trucks, the 4 speed is defiantly a slug compared to the newer 6 speeds; I'd say the 6.0/4 speed is pretty comparable to the 5.3/6 speed towing from my experiences.

flatblack83

I know my 03 2500hd lifted on 37s with 513 gears tows an 8k trailer pretty nice, now tho with the magnuson 1900 it does real well. Not the greatest on gas but it runs great.

ullose272

the trans in the 99-06 is a 4l80e and is hardly inferior, it doesnt have the gearing but its a stout tranny in stock form and even better with a kit.

DarkCharisma

no matter which way you cut it, the LQ4 is going to be down on power compared to the 8.1. One less forward gear in the 80e over the Allison, too.

The 6.0L is a fine puller, but I can't imagine you'll be satisfied after having the big block for so long.

FWIW I have pulled over 10k with my LQ4 and it's fine, just takes a bit to climb hills and you have to be willing to let it spin.