My swap. 5.3 into a 1990 3/4 ton 4x4 Suburban.

[y5mgisi]

No... Sadly there is quite a challenge getting a properly programmed computer for this truck. The problem being, im using a camaro harness and o2 sensors. This doesnt jive well with the 5.3 (truck) tuning. Ultimately, right now, im running a 5.3 tune and its nut reading the o2 sensors... So, my power seems about the same as with the LS1 tune, and my milage seems better. But i actually havent driven it much since i got it done, had it re painted, and got my 2012 Sierra. My long/short term plan is to rip the wiring all back out and start back from scratch using a combination of the ls1 harness and a normal truck harness. In doing so i will b e switching back to the truck o2's as well. There is a big list of hindsight issues at play here. So, it will be a while before i start driving it with any degree of consistency again, but when i do, i;ll report. Honestly tho, i feel that the 5.3 in a burb is pushing it. Its plenty of power, but its not got a lot of excess power. I think a 5.3 with a good tune, headers, and CAI is plenty well sufficient. I think if i had it all to do over, i probably wouldnt have done anything different. Its just the situation i was/am in. The old motor was so bad that it wouldnt have made it to where it is now. And i just really like everything about having a LS under the hood! But, In the end, the 5.3 wont stay in here forever. Its a place holder until i drop in a 6.0/6.2/8.1.

Bottom line, I would do a 5.3 swap into anything in a heart beat! THey just run good! They are cheap(ish) reliable, and just fun!