is my motor done for?

i have a 1985 chevy c10 2wd thats been sitting for awhile, i tried jump starting it the other day and it turns over slowly, the starter is almost new, and i messed with the cables to make sure there was a good connection.im not a hardcore gearhead so can anybody tell me if im missing something or if the motor seizing up, its a 350sb.
BTW this is my first ever forum post so i hope i did it right.  

Gonna need alittle more info. Have you changed the oil? Does it turn over easy?  

oil change-it was changed before it was parked but it looks clean on the dipstick now/    does it turn over easy-it just turns over very slow even when the batteries been charging for awhile. its been sitting for maybe 2 years  

The first thing I'd recommend is a new battery, first of all. If that doesn't seem to make much of a difference, I'd inspect all the cables & electrical to make sure they're in good shape. You might need new distributor points. But get a new battery first, and let us know if that makes a difference.  

thanks for the advice and i'll let you know if it worked  

Try to drain the fuel and put some new fuel in it.  If it's 2 year old fuel its going to be garbage.  You may need to get some fuel system cleaner aswell.  I heard that GM has some really good stuff.  It sounds like your truck isn't getting enough combustion.  Just an idea for you to try.  
-Cody

Good point. If it was stored for 2 years without fuel stabilizer, then chances are, the fuel is bad. Even with stabilizer, it's generally only good for 6-12 months. I'd get the carb cleaned (if it has one) Maybe pull the fuel pickup in the tank. If it's been sitting in rotten fuel, it probably needs to be cleaned or replaced.