dsadsdaiouser

We picked up a 2001 GMC 2WD with a 4.8L to tow our '04 Corvette Stock Eliminator car. The truck is IMMACULATE; body and interior are almost perfect. It's been a great truck however the 4.8L is beginning to use oil and has never had that much "get up and go" (we knew that it wouldn't when we bought it but it was so clean and the price was right).

Can we get a 5.3L or hopefully a 6.0L and swap it in? Will all the external engine accessories bolt right up? Also, regarding the computer, can I just take it to my tuner who uses HP Tuner and does the Corvette for get it calibrated correctly? Anyone with experience changing out a 4.8L with something bigger would be appreciated.

Thanks!

Blackpanther99

iTrader: (8)

Everything should swap right out from the 4.8 to the 5.3 or 6.0. The wiring harness from the 4.8 will work with the 5.3 just fine and I believe also for the 6.0 as long as its a Gen3 motor. Im sure the 4.8's PCM could be calibrated to work with the 5.3 and 6.0. Its pretty much a direct swap Not a expert but thas what I know

Edit: How many miles on the truck?

dsadsdaiouser

Getting close to 100,000. I haven't got down exactly how much oil it uses but I'm going to give a rough guess of 1/2 quart per 1,000 miles. Is this normal for a 4.8L? I've NEVER owned a vehicle that used oil so this is new to me. It gets decent mileage; about 20 on the highway and 17ish around town. It runs fine but we'd like more power as we're getting ready to buy a 24' enclosed trailer to pull our C5.

Blackpanther99

iTrader: (8)

Thats waaay too much killing oil for a 4.8L. Shouldnt be killing too much oil at those miles. Have you tried doing some maintenance?

dsadsdaiouser

We bought it about a year ago with 86,000 and obviously drive it a lot. I change the oil regularly and use only Mobil 1 synthetic. The truck appears brand new literally front to back and top to bottom. Since I've noticed it start using oil (seems like a recent thing) I switched on the last oil change to Mobil 1 synthetic high mileage and also put a quart of Lucas Oil something in it. I recall it was for oil consumption and remember it was about as thick as Vasoline!

What other types of maintenance should I perform since I've never owned a vehicle that uses oil and haven't had to deal with this before. I sincerely appreciate the input.

massconfusion

iTrader: (18)

kinda sounds like it might be the valve seals on the head or the rings might goin. kinda strange for that to happen at a 100k though

dsadsdaiouser

Yes, I thought the same thing and fear that no type of additive will help the problem. May switch next time from synthetic oil to regular high mileage.

Bowtie316

iTrader: (1)

A big enclosed is going to be a tough pull for a 4.8. What gear ratio in the rear?

The swap is simple as long as you use the correct gen motor. Just tell the tuner what year and size motor and they should be able to reflash the stock pcm to run the new motor be it 5.3 or 6.0. nothing else to change really, it's a bolt in affair.

dsadsdaiouser

I'm not sure of the gear ratio; that's a good question. I've tried to pull the codes in the glove box and research it on-line but can't find valid information or a good site to cross reference and find the answer. Do you happen to know what codes go with what gears?

The trailer we're going to purchase is #3500 (Pro Line out of Georgia) and our C5 is #3200 (we don't carry much other junk) so we'll be right at #6800 or so. East/Central Texas is pretty flat and we stay around here but I would like to have more "ump!"

What year range 5.3L or 6.0L should we look for? I'd like to buy a lower mileage one, take it apart just to ring it, put gaskets in, go through the heads, and perhaps put a cam in. I'm a HS math teacher in about 6 more weeks I have all summer to do the swap.