I have a 2000 Silverado with a 4.8 that has 261,000 miles on it. The motor runs fine but is starting to show signs of old age and high miles. I managed to get my hands on a 5.3 LM4 (Aluminum block) and transmission from a wrecked 2004 Envoy with 70,000 miles on it. From my understanding, I should be able to drop this motor into my truck after changing the oil pan. My concern is the tune. Will this be driveable for a week or 2 until I can get the tune? I will also be changng the throttle body, as the LM4 is drive by wire. Any help here would be appreciated.

 

if you use the same injectors it might run, I wouldn't drive it like that tho. mail tune or in person tune?

 

I would like to dyno tune or in person tune, but I dont know any one close to me that can do it. I have heard some horror stories about mail tunes, so I guess im still on the fence with this.

 

Yes you should be fine running on the 4.8 tune. The injectors should also be ok. Don't get crazy though. I drove a cam'd, full exhaust 6.0 on a 4.8 tune with a hypertech flash only for about 6 months, with no problems.

 

Where are you located at?

You can also consider getting an AutoCal unit from one of our vendors like Black Bear. It's a cable that allows you to read and flash files but the tuner makes all the changes and corrections It also allows you to data log while your driving so you can send the data to the tuner and he can make adjustments based on your Driving habits.

Black Bear Performance :: Custom Tuning Solutions for 96 and newer GM Vehicles

 

Im just north of Cincinnati, Oh in Lebanon. I would prefer to have it tuned in person, but the Autocal sounds promising. This may be the better choice if I decide to start adding bolt ons as well. I appreciate the information.