Nice find!Update:
Trans guy found a bunch of stuff wrong that none of us could have known. First, prior owner had a Powerdyne SC on it, when he took it off, he never changed the plugs. It still had the super cold plugs in it which was causing the cylinders not to fire reliably. Also, the distributor was clocked wrong, it wasn't set up right on the #1 cylinder (prior owner had put Eddy heads and a new cam in after SC was removed). The TV cable was adjusted right and it was getting full throttle, until you put the K&N filter housing on, then it stoped short of full throttle because the arm was hitting the bottom of the housing. He also found some bad settings in tune. He also changed a few things in the VB and adjusted pressure setting, he says it will bark 1-2 and 2-3 now. After he got the trans working right, he put it on the dyno for a tune, first pull was 204hp, he knew that was way too low and that's when he went looking for other things and he found the plugs, distributor and tune problems. After he fixed those, next pull was 275hp, he said it still too rich at 11.5:1. He going to adjust the fuel curve and run it again tomorrow. Guess that's what you get when you buy a used truck.