I don't have much experience in this area, but I would take the starter off, no big deal, and try it, if that doesn't work, I would take the head(s)off, I think it must be a v8, and see what was under there. It it still won't turn over, I would get a block of wood and a fairly heavy hammer, and I would give each piston a good whack or two. It that doesn't work, pour some oil in the cylinders, let it set for a day or so, and whack it again. I have heard of motors being stuck, and this method used over a long period, with the motor finally turning over and running ok for a long time.
If it set for only 8 months, it doesn't seem that it would be stuck very tight.
If you really want to see if the former owner lied to you, pull the heads, the starter, and the oil pan and look at it. You might have more problems than a stuck motor.
Even if you had a sraight transmission pulling it probably wouldn't work. The truck I am now working on had a stuck motor, and you could pull it all you wanted, and all that happened was the rear wheels draged. Allen
