85GT-79FJ40

If it was knocking I would suspect that there is some bottom end damage. I've never owned a 3.0 truck myself but I've driven plenty of them and I can't believe all the hate. I know of many that have gone well over 200k miles with little more than regular maintenance. As much as I like 22RE's they are pretty gutless stock and the 3.0 when fresh has more power. I suspect many of those complaining about not being able to keep up with traffic, getting 10mpg, etc. are running big tires with stock gears and are blaming the motor for poor performance. As for the OP I would tear it down, talk with a machine shop you trust and see what you find before ordering anything. Ordering internal engine components before a qualified machinist takes a look at everything is pretty foolish if you want it to run. Many machine shops can get components like this cheaper than you can find them online too. Until it's been looked at it's anyone's guess what size pistons and bearings you need, if it needs a crank, etc. The first step is taking it apart. It's not doing anyone any good in the truck so you may as well pull it and see where you stand.

CyMoN

could do a 2.7 swap I recently looked at some toyota parts a guy was selling and he had swapped a 22r for 3.0 in a T100 he claimed that he go better gas mileage but said it was slower.

if you swap for a 22re your also going to have to swap transmissions and maybe drive shafts. and wire harnesses and ECU.
I would put a 5 cylinder benz diesel in it

westjohns yota

im with 85 gt, if your head gaskets are done right, and your bottom end would be fresh, throw the thing back together, thats exactly what alot of people do, couple hundred pounds of bumpers, bigger tires, skidplate, you may not think an arb bumper would drop you gas milage but throw a winch of the front and couple of fog lights, youll get less air flow to the rad, makeing it run a little warmer dropping mpg, alos biggers tires and few extra hundred pounds adds up with that 6cy, we all agree the 3.0 isnt the best motor, but anything with a bunch of extra crap being lugged around isnt gonna win a race or get 20 mpg anyways, rebuild the 3.0 by a mechanic you trust, or throw a 3.4 in it