What would you put in a 99 K2500 suburban

[gthomas]

My wife drives a 99 K2500 suburban with a 5.7 engine and 133,000 miles. Friday we were heading off for a short vacation 11 hours away, and about an hour and a half into the trip the motor started sounding real bad. Stopped at a GMC dealer we were going by and had them take a look at it. Their verdict is a spun main bearing. They and my favorite local mechanic both recommend a new engine in this case. My vehicle is an 03 Avalanche with the 5.3 engine which I really like, much more than the 5.7 that was in the suburban. If I replace the engine, I'm seriously contemplating putting in an LS-based Gen III engine, probably a 6.0L. I'm hoping for much better fuel economy as well as better overall driveability. This being the wife's daily driver and generally full family hauler, I'm not so interested in performance gains in this vehicle, but I'd certainly take them if they came with the other desired benefits. I have never done an engine swap before, but I wouldn't mind giving this a shot, if it wasn't too bad of a swap.

What do you all think about this? Would a 6.0 give me the benefits I think it would over a 96-02 era 5.7? Would it bolt right up to the tranny as the 5.7 would? If I go this route, should I also go with a 4L80 tranny, and if I do, should it bolt up to the transfer case the same, or should I consider swapping engine, tranny and transfer case? I'm using HPTuners in my Avalanche, so tuning is something that I think I can handle. I imagine I'd need a new wiring harness, but it looks like I can get a 6.0 with PCM and accessories with low mileage for less than the GMC dealer who diagnosed the truck wanted for a crate 5.7 from gm.

[RedHeartbeat]

If you can get an engine PCM from a same year/model as your Avalance you will save using up your licenses on HPTuners. You can get a PCM and have it loaded with the base Av program and then tune it with your standard cable. I'd sure do the 6.0L engine but it's not going to be a straight swap. For simplicity and speed to get back up and going, it's hard to beat the 5.7L Vortec replacement engine. If you have the time to allow the vehicle to be down, the 6.0L is great. You can bolt the 6.0 to the suburban trans using a crankshaft spacer/extender. You'll need engine adapter plates, a wiring harness, fuel system connections, fly by wire throttle pedal and sending unit (if FBW not cable), radiator hoses, air intake system and a few other items. If your wife is anything like normal women, replace the 5.7L and be done with it, not worth the aggrevation.

[Tim Z]

i would def. put a 6.0 in it! it wont be that hard, just cost a little more to install but will definitley be worth it!!

[gthomas]

Thanks for your thoughts guys. I'd really like to go with the 6.0, but I'm not sure it would get that much better mileage. It would probably be a lot more enjoyable to drive, but it would probably not be too appreciated by the wife who usually drives that vehicle anyway. The thing has always been a real dog compared to my Z66 Avalanche with the 5.3, and that hasn't bothered the wife. If it were my daily driver, I would try to tackle the 6.0, but Redheartbeat's comments about women in general definitely apply here, and I'm going to be gone for several weeks for work at the end of July into August and I'd better have her back on the road before then, and I'm also super busy at work leading up to this business trip.