3G alternator conversion

[Joshgt87]

I'm putting a 3G alternator on my 76 250 with a 390. I understand I need to run a dual v belt. Has anyone else done this? The truck has a/c and power steering. I found a pulley from a company called tuff stuff but I'm not sure how to route it. Thanks guys!

[basketcase0302]

"Joshgt87"]I'm putting a 3G alternator on my 76 250 with a 390. I understand I need to run a dual v belt. Has anyone else done this? The truck has a/c and power steering. I found a pulley from a company called tuff stuff but I'm not sure how to route it. Thanks guys!

I don't remember ever seeing anyone having to change engine pulleys Josh-but I also never got the one in the garage put on yet.
This thread is a really...good source from a few guys who've done it though:
http://www.fordification.com/forum/view ... =8&t=13062

[BobbyFord]

AFAIK, you don't need dual belts on a 3G install. I have a 460 and run one belt.

[Ford-f100-1972]

I put a 3G on my 302 with one belt. Works just fine with ac and electric fan amp draw. Never slips.

[Manny]

Another member of the 3g club with single groove. Got two that way the 84' bronco and the 74' bronco.

[Joshgt87]

Hey awesome!! Thanks for the links and all the advice fellas! I'll give the single pulley a shot.

[Lee]

Not meaning to hi-jack this thread ,.... but you folks that have installed a 3G .... how hot does the case of the alternator get when running?

Within 60 seconds after start up, Mine gets hot enough you can't keep your finger on it.

Thanks,
Lee

[Ford-f100-1972]

That doesn't sound right. Mine gets warm but some of that is probably from engine heat.

[BobbyFord]

Not meaning to hi-jack this thread ,.... but you folks that have installed a 3G .... how hot does the case of the alternator get when running?

Within 60 seconds after start up, Mine gets hot enough you can't keep your finger on it.

Thanks,
Lee

What part of the engine can you keep your finger on at operating temp?
Not trying to be a jerk

[Ford-f100-1972]

Not trying to be a jerk here, either, but I can touch my alternator at operating temp. Too hot to touch after 60 seconds sounds excessive. Just sayin'...

[BobbyFord]

Not trying to be a jerk here, either, but I can touch my alternator at operating temp. Too hot to touch after 60 seconds sounds excessive. Just sayin'...

How old, weak is the battery?

[Eric46]

I am running a 3G (95amp) alternator on my 70 F-250 w/390. PA Performance (link below) has the electrical components needed to make the conversion...namely the high capacity lead wire and the conversion "voltage regulator" so your gages work. The alternator is the correct dimension so that the pulleys line up without having to shim it. They also have a 2V pulley if you want to run two belts. They have a pretty good tech section too.

http://www.paperformance.com/alternator ... 5-mustang/

r
Eric

[WhitsEnd]

There are different versions (amperage rating) of the 3G alternators. The 95 amp unit is fine with single belt. 120 amps will squeel if you run the wrong V belt, with less surface contact. Above that and you really should have 2 belts.

[mulletmobile]

Sorry was away from computer a while and thought I would chime in. I did the 130A alternator install on mine. Initially I did not have the two groove pulley but I ended up putting one on. I had some slippage and it was rectified by it. I sent out my amp gauge to a vendor who converted it to a volt gauge and harvested an alternator harness from the JY and using the factory wiring was able to install it cleanly looking almost factory. I also moved mine to a low mount using a bracket setup from a 67 Galaxie to get it down and away from the heat of the cylinder head. It runs good and cool now and I reccome d it. If you have any questions I did a thread on it and would do it again. The gauge cost me $25 to have converted and he can re-letter it too. Between brackets, pulley, gauge, maxi fuse and wiring (alt was a JY pull) I am in maybe $125.

[BobbyFord]

I have a 130A on mine with one belt and no belt squeal. Also, running Optima battery under the bed with 1 gauge cables.