help!cannot get sentra to start!

Here is the story. I own a 1983 nissan sentra. I got it for free, the guy who gave it to me said that it use to run, and then one day it stopped, he said it was the carb. So I figured I could easily fix the problem, I'm not a super mechanic but I know a thing or two. So I took the the car home and replaced the head gasket, the intake exhaust gasket, cleaned the cylinder bores, cleaned the inside of the head(it was so bad you couldnt see anything) replaced thermostat, checked out the cam and the timing belt. Everything is is great condition. and picked up a carb from the junkyard. So I put it all back together and tried to start it. It cranks well but it does not turn over. It's not the fuel pump because the guy before me replaced it, it's brand new, and I checked it the pressure is fine. I checked the spark plugs and I am getting a spark in all of them. The IC is in good shape. Ive checked the static timing. I adjusted my valves to proper specs. All the vacume hoses are in the correct order.???? ANd the carb seems to be in good shape. Any help, troubleshooting steps would be great thank you.

Try the distributor. Our Sentra would start but wouldn't crank over. Cost us $720.00 to fix but it works great now.

hope this helps
I have a sentra 1992 makeing a wide body kit for it now
well here are some things to looork at
leaking carburator ,fuel inject(s) faulty fuel pump ,pressure regulator
broken or stripped timing belt or chain
ignition components damp or damaged
worn, faulty or incorrectly gapped spark plugs
broken,loose or disconnected wiring in the starting circuit
loose distributor is changing ignition timing
broken or loose or disconnected wires at the ignition coil or faulty coil

Try the distributor. Our Sentra would start but wouldn't crank over. Cost us $720.00 to fix but it works great now.
are you saying your distributer cost $720?