i know i am new but i need help

ok here is the situation, i have a 93 suburban k1500. one morning i was driving it to work and i hit the gas pedal to pass someone and the engine died. i then coasted off the road and tried to start it agian it had juice when i turned the key to run position but when i turned it to start it it went dead. later that day i towed it home started to look around to see if i could find whats wrong. finally i figured it out. it seized up. i tried a bunch of stuff, taking out the spark plugs, wd40 in the hole there, manually turning it from the harmonic balancer then from the fly wheel. i finally got a small turn out of it when i used a bottle jack to push up on it. if any body has any ideas whats wrong or what to do please help.
thanks