That sounds scarily like me... My Grand dad gave me a '66 1/2 ton c-10... 2wd of course.. I had all the plans in my head when I was 15 and threw tons of money at it from that time untill I turned about 17. I had lots of fun just messing around with this truck, but in the end I realized, with my MONEY, SKILLS, and TOOlS, this truck was not going to be a 4x4. I dumped tons of money into performance parts for the old 283 (a few of which I'm gonna use on my suburban.) My recommendations would be to take the free truck and just save it back untill one day when you can restore it as a really nice 2wd. I would get a decent job and try to find a dirt cheap 4x4 from the 70's or 80's, and do as much research as you possibly can on this website.
The bottom line... you can never have to many trucks.. I LOVE that body style... one day you should restore it and make something you will always be proud of. I would not try to make it a wheeler, as it will probably just end up a piece of dissasembled crap under an oak tree, as do 90% of huge projects taken on by people without alot of resources. Save up and find a cheap 4x4 like I did. I paid $1000 for my burb... What's ironic is, I found out about the suburban being for sale when I was taking somebody on a ride in my old '66

So everything happens for a reason I guess, because without the old '66 I would not have the burb.. and now I'm just robbing parts off the old truck for the motor of the burb... I'm just saving the old truck back for when I have the money and tools to do a frame off resoration (when I'm 40 years old probably

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Hope my ramblings have helped you. I just wanted you to know that I have been in you exact situation once, and maybe you can learn from some of my mistakes (dumping money into something that was never meant to be a 4x4).
thanks,
James