i have a 87 bronco full size it has a 351w with a c6 trans and im haveing a starting problem i have repaiced my flywheel starter battery and starter sylnoid and the problem i am haveing is that my starter spins but it is not engaging with the flywheel

 

Not sure on the setup with yours, but either the solenoid hot wire is dead, or if it's a jumper between the solenoid and motor, it's missing or broken. Or, if there are 2 wires going to the solenoid, and you have power, then the ground wire is open, broken, or missing. Go over to the Bronco's forum and ask?