I'm pretty sure that if you have fixed alternator and a serpentine belt tensioner you need the 7" C-C version.

I know I used an 8.25" on my truck with V-belts, where the alternator is adjustable.

 

I recently have been wondering this same thing. My truck is 18 years old and I have personnally owned it for 17 of those years (bought used in 1995). In that time I am on my 4th alternator with 2 of the previous 3 catching on fire. I have been lucky that one was at a car wash and we grabbed a bucket of windowasher off the ground and dowsed it quickly. The other was also lucky to be in my driveway where I had access to a water hose. This has always scared the hell outta me. I think with the help of this thread and this awesome community I am going to initiate the change . I also have access at work to a machine shop so if anyone has dimensions of exactly how much to machine off the castings and where that would be awesome.

 

What engine do you have in your 1994 F150?

What do you want to machine?
The alternator bracket bolted to the block?
Look at the links on the first page of this thread.
You have to remove a section of web starting about 1/2" deep going to 0" over 2".

 

OK I read every single post and every single link. I believe I can handle this with no effort with the exception of how do you know which alternator to get? 130 would probably be great for me but I am having trouble figuring out which ones cross over from newer vehicles to mine.

Oh and its a 4.9l 300 and your right in your very first post in this thread I took it to mean something more than what was stated later in the article.

 

I'm not sure what type of front dress and belt tensioning is found on a '94 4.9.
So, I read in this post on FSB

FSB Forums - View Single Post - 3G Interchange Facts. If you're thinking 3G read here.

It says that you want a 8.25" (long ear) alternator to fit a '92-'97 I-6 300/4.9.

Assuming that is good information, then I can tell you it can be found in a '93-'96 3.8L SOHC V6 Taurus/Sable.
That's where I got mine.

Hope this helps!

 

Belt tensioning is just a serpentine with a tensioner. But for 25-30 dollars I can afford to screw up at the junkyard. You rock thank you.

 

The 8.25" looks a little different.
One quick way to identify it is that the "ears" are bridged and not solid looking like the 7".

8.25"


7"

 

The 7" pivot mount can be found in some of the newer 2000era with the v8 as well.

 

Well I picked up everything I need for my 3G swap except the MEGA Fuse and holder. Noticed the clocking on the alternator is off. Can it be changed? If so how? Thanks. Ill post pictures later.

 

Check the number of holes in the front, between the webs ...

I think the trucks had the smaller diameter (135mm) 95A side mount 3G




Not the larger 148mm Dia. 130A version.

 

Yes you can change the clocking.

1) Remove the pulley with an impact wrench..
2) Remove the three screws holding the halves together.
3) Do NOT let the cases separate more than 3/16 - 1/4"!
4) Turn the front to where you want, and reinsert the screws.
5) Tighten the screws and reinstall the pulley with the impact.

 

Can it be done without removing the pulley?

 

Not really easily.

The pulley will not allow the shaft to stay in the rear half.
If you use a paperclip to hold the brushes back in the holder then you might be able to do it but you must be careful that the rectifier stays in place with the rear half.

Here's an exploded view;


www.alternatorparts,com

 

Even_P Ard Wrkn Trk is giving you good directions on clocking ... If it will not split easily spray with mmm PB Blaster of your favorite ... then TAP lightly with a dead blow or plastic mallet *** YOU CAN BREAK THE CASE*** when I did mine I made sure the rear half stayed with the internal parts !!! I totally removed my "front" case half (no real need to remove front totally) Just lift it enough to clear the bumps on the side so you can rotate it where needed. When you re-assemble line up the 3 small bolt holes and put the case together evenly ... re-tighten small bolts use the impact for the pully... put on truck !!!

 

Yeah, if it is a used alternator you might need to tap around the seam with a leather or dead blow mallet to loosen the corrosion.

The case halves index with little tabs as shown in the exploded view.

once it is opened a little bit the two halves can move relative to one another.
Just line up the screw holes and tighten it back up.

I've never had to resort to penetrating fluid but could see how this might help if needed.
Use some electric motor or contact cleaner to dry up the slip rings and brushes so you don't end up with paste that will gunk them up if you do.

Really, if it comes down to it just go to the auto parts store and ask them if they can R&R the pulley for you.
(hold the pulley with a glove and hit it with an impact)
They do it all the time for people who buy reman alternators, none of which come with a pulley installed.