can u crank it over all the way smoothly without binding, by hand using a ratchet? my grandfather had/ has a '67 GMC K25 ( 4spd manual ) that my dad and him put a 350 in, and it ran, but started extremely hard due to the incorrect bell housing and it had a lot of resistance, took 2 battery's to get it to turn over fast enough to start, otherwise it would go over once or twice and bind. my thinking is the flex plate could be bent or loose, causing hard starting and binding.