Soon to be mine, but i have questions...

[SmokeShadows]

Long story short is that i had previously bought a 68 gmc that turned out to be a classic lemon, and well im in the process of obtaining a 69 gmc 2500 and i have a few questions and am hoping to receive some advice, any feedback is appreciated, i will post a few pictures of it and the spid, can you help me decode it, like the first option listed, and also i have a few concerns regarding the motor, i will be purchasing the truck with no motor because he wanted 2.5 times as much as im paying just for the engine, i have the motor out of the other truck i bought But its a later model 350 with a serpentine style belt, the true condition of the motor is unknown because I am concerned about taking it apart, but it does run decently from what I can tell, the old trucks tranny is a 700r4 and the new trucks transmission is a 4 speed granny, can i and should i just take the motor out and put it with the 4 speed and if so what will i need when doing this? Sorry if these are lame questions but i dont want to mess anything up when trying to get this 69 out on the road, and while trying to do this on a budget, should i rebuild the engine myself? If i take the motor apart and don't get it machined could i just put it back together no problem? Or should i just look for a motor on Craigslist? I need advice before i jump into it, i dont want to make any hastened bad decisions, thank you guys for any help!!