The motor wants to start. What can I do?

[mookiex4]

Good Day all.

I have a question. I installed a 283 into my 65 GMC. The motor had been on an engine stand for about 20 years in my dads garage.

It is in the truck and is getting fuel and spark. The engine is belching out some exhaust., but is is just hanging on the line of starting, it wont start. Am I missing something? I do know that the lead from the S connection on the starter solenoid is not connected to anything. The engine turns over and everything though. Is this keeping it form starting?

I hope someone can help me out.

Thanks,
Mark