Hello Folks- my 86 (10/85 manufacture, technically an ?85.5?) 720 driveshaft may or may not be out of phase-- the question is are all three yokes supposed to be parallel/ inline ? my front yoke is 90 degrees off from the two rear yokes which are inline with each other.. The Full Story below..
Was getting heavy vibrations between 60-70 mph
So I've done a number of things- replaced everything, may have put it together wrong at one point. Took it off the truck and had the carrier bearing and front u-joint pressed in, then took the rear in the next day. Put it back on and had less vibration, but still some. Took it in and a shop pulled shaft and balanced it for me, and now vibrates even less but it is still noticeable. Worse, now i look under truck and front yoke is 90 degrees to rear yokes so im wondering if i had it balanced while out of phase, and what will happen if i try to rotate it..
For now I'm hoping someone with close to the same truck can tell me how their yokes are aligned and i can go from there, thanks in advance.

and Ok folks after years of finding every answer on this forum i have one i cant find first time posting but owe you all a great many thanks for getting me through quite a few repairs...

well, i've been reassured by the driveline shop that the shaft is ok and phased, guy says it is a combination of i have become paranoid and oversensitive // old car will shake a little// he drove it on freeway and said everything was fine BUT also told me it may be harmonic balancer, or even a bent rim (one look suspicious to him) .. basically i will look it over again and drive it until it gets worse... figured this info may be of help to others with same problem, once driveshaft is all good the wheels, harmonic balancer, and even possibly a loose pressure plate could be the culprit, or it could just plain be so old that it will shake a little... Bottom line getting drive shaft balanced and checked helped a lot and the other problems are less likely to result in stranding me/