I purchased a used long block, and installed a clutch. I could turn the crank completely around after that. I put the gear box on. I could crank it completely. I went through the timing belt procedure, and everything has been timed correctly. The belt is on now, but when testing to make sure I can turn it twice over, it will only go from about 12 O'clock to 5 O'clock. Something is holding it. What are my next steps to take?