Well worth it, got great milage, 3:73 gears granny 4 spd with a ranger overdrive. PM me or call me i'll walk ya through what i know. Soon as i get back to my actual computor i will edit this with a short how and what to look out for, typing onmy dumb phone is a pain.
Joe S. (307)-282-0773
Edit...
If your going to do the junkyard conversion from a 6.5..... look for the "GM-3" turbo setup. this was used around 93-94. the reason is the turbo wastegate is mechanical. You can cut the tin can off and use the internal spring with a nut/washer and have an adjustable wastegate. 14PSI is the majic number for 6.2's as any more runs the risk of blowing head gaskets. 6.2's are naturally aspir high compression engines pushing approx 22-1 compression, 6.5 turbos are low compression pushing approx 14-1 or 16-1 compression...
I studed mine with ARP and new gaskets when I turbo'ed it, some guys use the 6.5 heads as they are supposed to flow better for coolant.
Keep your 6.2 injection pump as its mechanical and turn the fuel screw up about 3/4-1 turn, depending on elevation. ( l lived at 8500ft and had it turned up 2 turns and it would fog out those behind me.. I finally worked it down to a happy spot.
I had to have my machinist brother mill me a 3/8 spacer plate that I ran between the 6.5 turbo manifold and the head, reason was so that I could get to the glow plugs on the passenger side... I figure if you run the 6.5 heads this shouldnt be an issue.
Turbo drain will have to be fabbed into the oil pan, this is farely simple with a mig welder and some plate steel tapped to 1/2 pipe, the drain tube off the turbo is avialible from GM for modest $.... I suggest swapping out the starter to a gear reduction, (big $ but well worth it) as this will allow you more options to weld the bung in the oil pan for the turbo drain.
Turbo oil feed can be gathered from the back of the block where the oil pressure sending unit is... just remember this line needs to be flexible as I used steel tranny cooler line and a $0.50 fitting snapped and cost me a $2500 (my labor + parts) rebuild and a toasted crank.
I sold this engine some years ago as I was putting a 24v Cummins in my truck... the 6.2 had a tendency to heat up on tows and long hills. I loved the milage, (mid 20s on veggy oil/diesel mix) with the ranger OD I had 8 forward gears with a 27* overdrive. I could go from Moorcroft Wyoming to Ft Collins CO on one tank of diesel, in a 4x4 dually crew cab that weighed around 7500lbs fighing wind at highway speeds....