I need help. I am going to be putting a 350 V8 into a '94 ranger. I need to either overhaul the differential or buy a new one. I need some tips on what I can do.

 

Rear or front, and what driveline was in the Ranger stock (yes there were 2 different front and rear axles available)? The front there is no upgrade. The rear is pretty much the same boat, but there are a few things. The best thing to do for the rear is to swap out the stock axle for a 9". The 8.8 might hold up for a while to high horsepower, but don't be suprised if you break carrier or ring gear teeth.

 

My 94 Ranger has a stock 8.8", 3.73 with 28-spline axle shafts. If I ever dropped a V-8 in it I would do nothing but drive it. I know 8.8" is factory because my Uncle purchased this truck new. I installed an Eaton-Posi in the baby about a year and a half ago.

 

Well as I recall even in 94 the only Rangers to get the 8.8 had the 4.0L. If you had the 2.3L or 3.0L you still got the 7.5. The 7.5 won't hold up to a 302 for very long, let alone a 350. Last 2 guys in wheel with in my ranger club have RBV with 302s swapped in. They still had the 7.5 in them until they blew them up. Well one lasted half a trip, the other about 3. The 8.8 will handle it better, but if I was doing it I'd go with a 9". Ideally I'd try and find a big bearing, 31 spline, cut it to width, and redrill the shafts to 5x4.5" pattern.

 

Aftermarket parts application catalogs listed all 2.3L Rangers to have the 7.5" diff. That must have changed for 1994. Vehicle was assembled on 2/10/94. Axle tag Julian date reads: 4B01, which indicates axle was assembled on 2/01/94. Engine tag still on engine, I believe it is 2/01/94. from Lima, OH engine plant. I even checked out the axle code on a Ranger site and everything matched for Ranger (open diff.) with 3.73 ratio.

I was so amazed that this 4 cyl. Ranger having an 8.8"; before I installed the Eaton-Posi, I called the local Ford dealer to verify the R/H axle shaft part# per his microfiche--yes, vehicle was produced with 8.8" diff. and part# on R/H axle shaft was for 8.8" with 28-spline (I worked light and heavy duty drivetrain, retail for 23 years). I don't work in retail anymore.

This vehicle only had 16,800 miles on it when I purchased it last year. Nothing special: just XLT trim, long bed, reg. cab with alloy wheels & A/T.

 

So where can I find a 9" rear diff? I am trying to get most of my stuff from the junk yards, so what truck would that be off of? Would the 8.8 work with the 350? If so, I might get lucky and have that on my truck. Also, where online can I order the posi for it?

 

Sounds like you will need to get a drum to drum 9" from a salvage yard. Assembly will need to be cut down and axles re-splined. One word of caution: 9" is not ABS compatible. You may have issues with vehicle computer / ABS system.

 

Well, I am going to only be doing about 325 HP, and definately will be adding a posi to whatever differential I use, 8.8 or 9. I am getting mixed reviews on the 8.8 and 9. Some say the 8.8 will hold up and some say it won't. so would I be able to use the 8.8 if I am lucky enough to have that already on the truck?

 

From an engineering standpoint, the 8.8" is a better unit than the 9". 9" has more aftermarket parts available and has come to be universally accepted throught the short tracks in N. America for the ease of gear changes & parts availability.

The downside of the 9": the design (pinion position relation to ring gear centerline) makes the pinion want to push out the front of the carrier assembly. 9" was designed and implemented in the mid 1950's, when car manufactuers were building cars that were very low to the ground. Design influence was placed on a unit that would move the pinion lower in the chassis; 9" was just what was needed. Memory tells me that Ford produced the 9" from about 1957 to 1985??

I would put an 8.8" up against a 9" any day, as long as the 8.8" was manufctured after 1985. 1985 introduced a larger spider pin and beefier axle gears and spider gears.

I have built many 9" Fords that are in race cars running 600 H/P and up. I would build 8.8" for race cars if the teams could change ratio as easy as a 9".

 

so the 8.8 would be the way to go. Sounds good. I am not going to be doing any racing, except bring it to the drag strip once or twice to try it out and see what it runs. I am mainly doing for 2 reasons. 1. beat all of the hondas with fart bags , I think it would be funny to beat them with an old rusted ranger, and also 2. beat my bother-in-law in his gm car (hopefully) because he likes to spend a lot of money on new cars and that would be great to beat him in a 94 ford, even though it will be a GM engine. He would hate that....