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I finally got the front driveshaft back from the shop and put it in this morning. Hubs locked in I can still freely turn the driveline. I took and drove it and sure eonough it doesn't turn. What now?  

It sounds like you might have 2 problems!
If you can turn the drive shaft with the vehicle in park and the front hubs locked your transfer case is not in 4wd and you may have a problem with a locking hub.

With both hubs locked jack up one wheel and see if you can turn the wheel. If you can you might have a hub issue.

What year is the truck, what transfer case do you have, & what front axle  

It is a 1986 K2500 GMC, it has the chain drive T-case (np203?) and I am pretty sure a dana44 front diff. When I checked, it was in gear (manual trans), hubs locked sitting on the ground.  

If its stock, the original t-case anyway, it should be a NP208. If the housing is all aluminum it is. As for the front, it would be a 8.5 10 bolt.  

Yes, the t-case is all aluminum and has been replaced once but it is OEM. The front diff. came from a '78 3/4ton and I am 90% sure it is a dana44. I did note yesterday that one hub has been replaced and the other is still original. One bad one would cause this problem wouldn't it?  

Yes on problem. On axle it could be either axle (D44 or 10 bolt) as 78 is the year that GM started to change over to 10 bolt and by 79 they were all 10 bolt. No loss if it is a 10 bolt as they are both about same strength.  

So I've been told on the strength although I was disappointed to find out it wasn't a dana60. I thought a 3/4 ton would be a heavy rig all through. It seems to me they used 1 ton rear drive and 1/2 ton front drive. I don't use it that hard (yet) so I'll assume the lighter T-case and fron diff will be okay but I do wish now I'd have taken the 1 ton the guy had instead. This one had a new engine and a 4-speed, the one ton was auto (condition unknown) and no engine in the hole and they were thw same money (cheap). If I am reading the numbers and taking the desription you guys gave me on the other thread properly I think this one is a Dana. Do you have any preference on front hubs, I think I'll replace them both.  

Warn make a good hub as does Spicer if you have a D44. You want to grease them very lightly when you install them (just a very thin film) or they will fail in cold weather. (you do not want to pack them with grease) BTW, 3/4 ton NEVER came with D60 up front. Some would have you believe otherwise but they never did. Up through 87 the only difference between a 1/2 ton and a 3/4 ton front drive axle was the hubs/bolt pattern. THe were the same spindles to pig otherwise and all you had to do was swap wheel hubs to convert for a 1/2 ton axle to a 3/4 ton axle. Just about all 1 tons then had a D60 up front but a few SRW ones made it out with D44/10 bolt up front over the years. They were kinda rare and lightly because of a axle shortage.  

That is what I've learned, I assumed and din't check anything about the front diff, I only assumed a 3/4 had the 60. Supposing I wanted to change the out, a 60 out of a one ton should bolt right in shouldn't it? Maybe I should worry more about trashing the T-case? Maybe  they are all fine? Thanks for the info.  

There is nothing wrong with a 208. It has proven to be a sturdy unit. People that have trouble with them never change fluid in them (which I would do now if you just got truck or you have never changed it and it takes Dexron ATF fluid) or they are running big tire with tall stock axle and depend on low range a lot to try to bail them out. Lo range was never designed for that and it takes a toll.If you are running 33 to 35's with a 3 speed automatic with 4.56 and change fluid every few engine oil changes, you will not have any problems with Tcase. FOr some reason many are hung up on tall axle ratios and figure it is Tcases job to bail them out off road and they will sometimes spend a fortune on HD cases, driveshafts, Ujoints, trannies and what have you when they could have spent some money on axle gears instead and not only prevented other drive line problems but gotten a nice performance boost too.  

Hey Sno, what about in the early 70s when Dana 44s had those smaller bearings on the 1/2 tons? I ran into that on a 75 Chevy I had that the front inner wheel bearings were smaller than the size on 10 bolts. I used to remember the part numbers but cant now. I have never seen this on any other truck I've worked on before. Also, when changing the frontends from 6 lug to 8 lug, I have always had to change the backing plate also. If you just change the hub/rotor assy, the brakes usually don't fit. Is this because of the 8600GVW calipers or what?  

Bearing size is a function of hub, spindle is the same but you make have to change bearings.  

One more for ya, Sno; what about those big hub spicer Dana 44s. I know alot of people get these mixed up with the D60s. I think thats why some will say the 3/4 ton trucks came with D60s. I was looking at trucks about a month ago and for another project and the ad said it was a 1 ton and I get there to look at it and find that it is the big Spicer hubbed D44. I explained to the guy that the emblem on the side of the truck, the GVWR, and the D44 verified the truck was only 3/4 ton and he argued with me about it. I would've bought the truck but after he was biligerent about it I changed my mind. It was a steal for $300. The truck is still there with the for sale signs in it. They are changed to 3/4 ton though.  

My old 72 GMC 3/4 ton 4x4 (it was 2 years old when I got it) had those big hubs you are talking about on a D44. I think 72 was last year for that but I am not sure. It had a D60 in rear too.  

Well, from what I have came up with as for when they stopped using them, I think it was 76. On Fords, they were 77. I know this because they had the RED knobs and I thought it was stupid that Ford used those when their color is blug. I had a set of those off a Ford and needless to say, someone decided they needed them more than I did.
Do you still have the 72? I regret the two worst days in my life... When I sold my 72 3/4 ton 4x4 and my 69 2WD.