I just swappd a "95 f150 5.0 into my '69 bronco but have some tech q's. I installed the Holey pro injection so I just used the block and valves off the new motor, with no computer. However I would like to retain the serp. belt minus the a/c pump and air pump. Does anyone know if this is possible and if so what size belt and how do I connect the new alt. to old wirring? I also posted this on the f150 forum.

 

Check in with Motorsports. I think they sell and idler to delete those pulleys for a Mustang and it might work on a F-150 setup as well. You might want to ask that question on the 289-302 forum as well someone over there might also know the proper belt to use too.

What does the back of that alternator look like? If it has one big lug in the 6 oclock position, a smaller lug next to that and then and ASI or there wire plug at 4:30 and then to the middle of the alternator you have another lug you hav a 3G alternator.

What you do is run a 6 guage wire from the big lug at 6 to the + side of the starter solenoid. You should also install a 175 Amp Mega fuse on that 6 gauge wire between the alternator and solenoid or you are out of your mind because a 3G alternator is capable of fryin' out your stock harness, whereas that old 40 amp thing you had was just enough to power up the AM radio. The lug in the center of the alternator you run to a ground. Use a decent guage wire for that to, like 10 guage. The rest of these connections you can run in 14 or 16 guage, or cut and crimp what was on the alternator factory.
Link the A terminal (ternimal closest to the two lugs) on the three terminal output to the big lug with the 6 guage wire going to the hot side of the starter solenoid. The terminal next to the A terminal goes to the stator, which is in between the big lug and the three terminal output. The I terminal goes to an ignition hot lead, which is the "I" side of your factory starter solenoid.