Hey guys, I've been on ls1tech for a while and just traded my 95 bird for a 99 silverado 2500. I got a couple questions I'm hoping you can point me in the right direction. Currently the trucks got a spun bearing 6.0 with the 4l80e and 3.73. Don't plan to tow a ton, maybe my 19 ft boat or a small pop up. my concern is having decent mpgs. So I'm wondering if I rebuild the current motor? Or I was considering putting a junkyard 5.3 in it for a little better mileage. Searching reveals little about this swap down, maybe for good reason. Any help is appreciated. Thanks!

 

Welcome to the truck side. I'd stick with the 6.0 if IMO. MPGs aren't a bog difference if you drive it decently. I average 12 - 13mpg with my 5.3 when I'm playing around town. But on the long trips I get 19-20.
6.0 will have a better resale and more desirable as well but I doubt that's what your after.

There's a few guys from your neck of the woods. I'm from Grand Rapids area. Gl with your future plans.