5.3 swap with 6.0

DEEZRACING · October 10, 2004

I have a 99 4x4 Chevy extended cab with the 5.3 in it. I pull a toyhauler wighing about 8000 lbs fully loaded. I have regeared my truck and now have 456 gears in it but its still a dog when towing up steep hills. I have an 8 inch lift and Im running 35 inch tires as wells which obviously doesn't help my towing at all. I have heard the 6.0 has a lot more torch and is a great motor for towing. I was wondering what it woudl take to to a swap from my 5.3 to a 6.0. Would I have to change to computer and what elese would be intailed in the swap? Is this even feasable? Any info would help..Thanks.

piratebaseball · October 10, 2004

From what I understand from ls1tech.com, you do not have to change anything to put the 6.0 in from a 5.3 engine bay. The only thing you may want to do is call nelson performance and have it customize your pcm for the 6.0. If what you are wanting is some low in grunt, however. You'll be better off keeping the 5.3 liter and adding a whipple or a magnacharger to the engine. You'll have alot more low end torque than you will wiht the 6.0 and the swap will be alot easier.

I have a 99 4x4 Chevy extended cab with the 5.3 in it. I pull a toyhauler wighing about 8000 lbs fully loaded. I have regeared my truck and now have 456 gears in it but its still a dog when towing up steep hills. I have an 8 inch lift and Im running 35 inch tires as wells which obviously doesn't help my towing at all. I have heard the 6.0 has a lot more torch and is a great motor for towing. I was wondering what it woudl take to to a swap from my 5.3 to a 6.0. Would I have to change to computer and what elese would be intailed in the swap? Is this even feasable? Any info would help..Thanks.

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02denali · October 10, 2004

heck yay a direct swap. get it tuned as well. what gears are you running.

99Silver6.0 · October 10, 2004

Easy direct swap! 6.0 can be picked up pretty cheap too. Plus the 6.0 will run on 5.3 tuning till you can get a full tune on the dyno or something. You will be happy with the gains from the swap! I hope you dont have a peg leg diff though!

On another note! Your 4l60 will most definitely die behind a 6.0. Quesiton is how long it will actually last. So beware! Im gonna buy a tranny before I put my motor in. My tranny is already slipping.

DEEZRACING · October 10, 2004

Thanks for the info... I went from running 373's to 456's and it really helped being that I am running 35 inch tires. The basic problems that I face is that I have steep grades that i must pass whenever I haul my trailer anywhere. I have a 6 inch suspension lift with a 3 inch body lift and the body lift is cutting of my airflow to the radiator thus casuing my truck to run about 230 degrees until I reach the summit of the hills that I must pass. I do not like it to run hot like this but upto this point I have had no choice. I have no problems hauling my trailer on flat land but even with the regearing and the minimal upgrades that i have made it is still a dog going up any hills. I just need more power and figured a 6.0 would be easy enough to do if I got the chance and if it wasn't going to cause any major problems with the compture..

99Silver6.0 · October 10, 2004

Thanks for the info... I went from running 373's to 456's and it really helped being that I am running 35 inch tires. The basic problems that I face is that I have steep grades that i must pass whenever I haul my trailer anywhere. I have a 6 inch suspension lift with a 3 inch body lift and the body lift is cutting of my airflow to the radiator thus casuing my truck to run about 230 degrees until I reach the summit of the hills that I must pass. I do not like it to run hot like this but upto this point I have had no choice. I have no problems hauling my trailer on flat land but even with the regearing and the minimal upgrades that i have made it is still a dog going up any hills. I just need more power and figured a 6.0 would be easy enough to do if I got the chance and if it wasn't going to cause any major problems with the compture..

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You are going to want to give the tranny some serious attention man!! Or else it is not gonna last very long at all! Especially with the tall gears, big tires and more TQ!

2ksleeper · October 11, 2004

It is a direct swap, you just have to get tuning for the new engine. You need to make sure you get a 2001 or newer. The older 6 liter with cast iron heads & the older crankshaft has a fitmant problem with mating the 6 liter to a 4l60e trans, the newer 6 liters with aluminum heads has a crank that mates up with the 4l60e.