Starting Problems ???

Hello All, As you can see I'm a newbie here! Heres my problem? I have a 307 eng from a 85 delta 88 for which I installed into a 1985 GMC G15 Van. The thing is this! I took it out on the road for about an hour, just around town. It ran great, then suddenly at a light it stalled. tried to start it again, and nothing, not even a click. I then let it sit for less then 1 minute, and bingo it started, but then stalled again after a few seconds, and the same thing tried to start it and nothing. Well needless to say I got it home, with a pull chain of course. So I let it sit overnite went out in the morning turn the key and it cranked so I turned the key back to the off possition and tried to start it again, and nothing. the battery gives me a reading of 12.5V so it's not power, I'm sure it's a short somewhere but can't pin-point it. any suggestions will be greatful.

My 1st thought: is to jump the starter then if it starts, I would have narrowed it down to the ignition switch??, ignition lock cylinder?? or the accuator arm?? and if it don't crank it could be the stater switch (solenoid) I hope i'm on the right track, what do you think! what else should I check, I know the spark plug wires are in bad shape had to tape some of the insulation, replaced fuel filter, PCV , and spark Plugs.

Thanks in advance!

Al

I would check for a loose connection for the ignition,firewall,distributor,any connector or wire that was moved or disconnected and reconnected during the changeover. good luck

The ignition problem has been solved. replaced the dist cap, rotor, and new wires. the old wires where shot, cracked etc.