Hey everyone,
I want everyone's opinion on this. I'm looking for the best differential to use in my 9 inch in my 79 ranchero. I have about 320-330 horsepower, and due to the fact that it has a bed, i probably won't have the great of traction. Im going to use 3.70 gears, but I dont know which differential to use. I had my mind set on Summit's detroit locker. Although it will be good for the track, i would like it to take sharp corners on the street, and im afraid a locker wont be that great and will probably cause oversteer or understeer. I hear bad things about everything else though, so i dont know what to use. I was told a limited slip would do good, but i heard the traction-loc isnt that great. I also looked at the Auburn Pro LSD, but i heard its not great either. If anyone has experience or could tell me which would give me great 2 wheel traction for race, but be able to take corners on street, please tell me!!! Thanks!
Danny

 

I am using the old 60's style equa-lock I got for a good price along with 3.70 gears. it was a little hard to find the replacement clutch discs and plates due to their rareness but I'm real happy with its performance.
I think any limited slip will be a world of difference in these light rear end trucks.
what dia tires will you be running with the gear swap?

 

im using 28 inch tires (275/60R15) BF Goodrich radials. Ill be running abou 27-2800 rpm at 60, which is just about the max you want for streetable on a small block i think. I may go with the auburn just because i can buy it new. I dont know if i want to go looking for an equa lock and rebuild it. But how does the auburn pro compare to the ford tracktion-lock?

 

yeah thats about the limit for comfortable street use. I have 255/60/15 on the rear now which is about 27". 28" are probably just right.

definitly a couple steps above the traction lok the auburn is going to be more agressive but you should still be fine in corners. the pro series is supossed to be really good. maybe someone can vouch for that.

 

alright, thanks for your help! Ill order that at Jegs, dont know why it isnt at Summit, usually they both have the same. The only thing i noticed about the auburn pro is that it says must use ford ring gear bolts for an open carrier, not the LSD because they are too long. Do you think the richmond gear install kit has the right length? Because they have a separate install kit just for the 9-inch traction-lock, and the other is for the 9 inch. Thats my guess. Thanks again!

 

by the way, do you know any ways to get better traction, other than the rearend? have you used traction bars (or know which ones to use since they don't make it ranchero specific)?

 

if you plan on replacing the upper control arm bushings. grind the nubs or teeth off both sides of the steel insert of the bushing. this lets the control arms move freely which helps the front end lift a good deal to transfer some weight to the rear. I didn't notice any loss in handling.

I think the open carrier thread length is 3/4 and the limited slip units are 7/8 or 1". not real sure on that. so you what you would need is 7/16-20 x 3/4 if thats the case. I'm sure the guys on the trans, diff and rear end forum would know for sure.