IT WILL NOT START

I installed a new p/s box on mt 67 barracuda. All i did was i removed the alternator, dropped the steering, and unhooked the lt header. I went to take it for a test drive and it will not start. It turns over and getting fuel. I have a MSD box, coil and distributor that are all new. I cant find any loose or unplugged wires. I checked and i am not getting any spark to the plugs or from the coil.