Newbie with a high mileage 4.8l

[decksetter]

Sup site!

I just bought a '00 GMC rclb 4x4 with a 4.8 about a month ago... with 240k miles. Has a rear main seal leak (not too bad yet) and I think I may need to replace the oil pump (or just put in a 5.3 or 6.0......). I only gave $2750 for it, couldn't pass it up!

I'm mainly going to use it as a work truck, probably try to get the fuel economy up some more (gets 2-3mpg better than the '97 Dakota 5.2l 5spd it's replacing). I'm considering lowering it an inch or 3 to help my economy, I drive mostly highway.

[kerrige]

Man that is a sick deal. If you are worried about mileage don't get a 6.0 Best way other than keeping your foot out of it to up fuel mileage is a custom tune from NP. I think if you loose the shell, get some better wheels, level it(2" down in the rear) and debadge/remove trim it would be sitting really nice.

[1BadCC]

Welcome to the site

[decksetter]

Man that is a sick deal. If you are worried about mileage don't get a 6.0 Best way other than keeping your foot out of it to up fuel mileage is a custom tune from NP. I think if you loose the shell, get some better wheels, level it(2" down in the rear) and debadge/remove trim it would be sitting really nice.

Well the other side of it is I have a couple antique tractors I take to a few shows, so the 4.8 might be a little underpowered down low for towing (probably 7000-8500lbs).

I'm not a big fan of the topper either, but I haul tools every day and it keeps 'em dry so it'll have to stay for now at least. As much as I prefer a tonneau, I can't fit some of my stuff under it.

[kerrige]

At least you have a good reason. If you just swapped in a 5.3 with a mild cam you will be better off for mileage and get good towing capability. Also the 60e trans is likely a ticking time bomb same goes for G80 rear end. I would swap to 80e trans and some kind of rear end upgrade. A valuetrac and some 4.10's would help you out a bunch.