upgrade.... maybe

[greg_carey75]

I have a 2001 with a 5.3L, it has 178k miles on it. I find it is underpowered for highway driving and terribly ******* fuel. Does anyone have any suggestions to increase the mpg/power? Is it an option to put the 6.0l in there?
Thanks

 

[NathanJax]

6.0 is always an option, and has been done, but for the money you spend doing it to an 11 year old vehicle, you could probably fine a newer vehicle with the 6.0 already in it.

 

[jdpber]

i vote crame the 8.1 in it and call it a day.. the difference from a 5.3 to the 6.0 in my opinion are minimal.. i have driven both. and i feel that the 6.0 shines when it has a blower and multiple mods. that is my 2 cents.. also remember this is a 6,000# hunk of steel it is not going to zip around like a porsche..

 

[Donnie Yukonie]

X2 on this drove a 8.1 2500 suburban about a week ago and that thing was a MONSTER i was very impressed and it did ok on fuel for nearly a 500 cubic inch motor i think i avaraged 15mpg until u put some pedal into it then it got around 12. But as stated these are 6k beasts they are not supposed to be quick or effiecent. Just badarse

Sent from my DROID4 using Tapatalk 2

 

[CEN2MENTAL95]

I owned a 5.3 01 tahoe with 130k...and now currently own an 05 denali 6.0 with 63k....there is a HUGE difference between throttle response on both vehicles....if you got the cash, dump a 6.0 in there

or just sell it and buy an escalade or denali with the motor already stock!

 

[PwtrSS_OakCliff]

Longtube headers, exhaust system, MAF sensor, or Throttle body. Small bolt-ons save gas and get you some power. Here in dallas, TX i can find a complete 6.0L for about $1000. I have seen people used one of these (LQ9) 6.0 with forced inductions since compression is lower than and LS1. The only bad thing is the Iron Block is about 400# heavier. I would just install an LS2 6.0 from a wrecked GTO

 

[imi4tth3w]

6.0 is a pretty tried and true swap. but it is going to be a pretty big cost. you also have to think about upgrading the trans as well as a 4l60 in stock form will not last long behind a 6.0.

don't even consider the 8.1. aftermarket parts are very expensive, will require a 4l80 swap, and will be MUCH more expensive. unless your really hard set on one, which from the sound of it your not, i wouldn't bother.

find a used 6.0. do some basic maintenance depending on the mileage, bolt ons (if you already have some for your 5.3, they should swap right onto the 6.0), etc. upgrading your transmission will be a requirement as well. FLT (finish line transmissions) are well known for making some nice transmissions. give them a call with what your running and goals and they will figure out which level will suit you best. a higher stall/converter will also give you better power.

check out performancetrucks.net lots of great info there.



now here is what i should have asked in the first place. what set up do you have on your truck now? what year/make/wheels/tires/suspension/performance parts do you have now? why is it such a dog? with my 35's on 3.73 gears my truck will still move on the highway even with 192k. 5.3 with intake, exhaust, vette servo, bb tune 93 oct, and she'll still move quite nicely.

 

[PwtrSS_OakCliff]

6.0 is a pretty tried and true swap. but it is going to be a pretty big cost. you also have to think about upgrading the trans as well as a 4l60 in stock form will not last long behind a 6.0.

don't even consider the 8.1. aftermarket parts are very expensive, will require a 4l80 swap, and will be MUCH more expensive. unless your really hard set on one, which from the sound of it your not, i wouldn't bother.

find a used 6.0. do some basic maintenance depending on the mileage, bolt ons (if you already have some for your 5.3, they should swap right onto the 6.0), etc. upgrading your transmission will be a requirement as well. FLT (finish line transmissions) are well known for making some nice transmissions. give them a call with what your running and goals and they will figure out which level will suit you best. a higher stall/converter will also give you better power.

check out performancetrucks.net lots of great info there.



now here is what i should have asked in the first place. what set up do you have on your truck now? what year/make/wheels/tires/suspension/performance parts do you have now? why is it such a dog? with my 35's on 3.73 gears my truck will still move on the highway even with 192k. 5.3 with intake, exhaust, vette servo, bb tune 93 oct, and she'll still move quite nicely.

If this guy goes to FLT he is looking at an easy 3 grand out the door. But Vince does a really nice job with FLT. Better of getting a used 4l80e from junkyard ($800-$1000).

I think the 4L60e will hold for a couple years. Not a big difference from a stock 6.0(LQ9) motor which have a Hydra-Matic 4L65-E 4-speed electronic automatic with tow/haul mode

 

[WildBill]

Im also curious about the OP and his set up. If its in good mechanical condition it should be that much of a dog. as stated earlier they arent too bad even with big tires on them. You wont win any races, but you can still pass.

Also, whats "Terrible" mileage?

Mod the 5.3 before you do a motor swap.