how can i stop my crank from jamming?

i have a ford luton transit, 2.5d, non turbo. the other day it just died, i stripped it out and it had bent 4 push rods. we put 8 new push rods in, put a new timing belt on and set timing up. i put a socket on the crank and gave it a few turns and it just locked up,the crank is still jamming. if i turn the socket anti clockwise it will un jam itself and will put itself into the original postion. however before i changed the push rods the crank was swinging over off the key no problem at all but just wouldnt fire up. please can somebody help me!!!