8 inch rear end

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Ive heard of 8 inchers handling up to 500 hp, but im guessing thats at the crank.

Ive been looking into upgrading my rear end as well. So far ive found that finding parts for te ole 8" isnt very easy. That and upgrading to posi is pretty expensive, $400+ just for the unit. Ive looked at upgrading to a 9 but thatll cost over a grand easy... anyway thats what ive found thus far.

If anybody else has some input im interested to hear it as im in a similair situation.
 
the 8" will handle the power your engine is putting out with few issues. you can even run slicks if you want. check out currie enterprises for 8" performance parts. the cost of building an 8" and a 9" is going to be about the same overall. differentials, gears, axles, bearings, etc. are all about the same price.
 
It depends on what you have for a trans (manual or auto), what year the rear end is (later ones are a little stronger, but I dont know when they changed), tire size/type, and how you drive it. If you have an auto and street tires, youll be fine.
 
The 8" will handle that power level just fine. I replaced my open differential with a newly built True Trac or Traction Lock (I forget which is is) for $600. It was setup with 3.80:1 gearset, which was perfect for my T5 trans. I also looked into going to a 9", but the cost was significantly more unless you find a good deal in the classifieds.
 
I am still using my 8" rear and have tons of 11 second runs on it. The automatic helps the rear end live greatly over a hard hitting stick car. Good traction bars that stop wheel hop are also a must. Wheel hop will break rear end parts.

All I have done is studded the pinion support (cheap and easy with 5 studs, hardened washers and lock nuts) and added a Detroit locker. I am also running some tame 3.55 gears which also helps keep it alive by having less torque multiplication off the line. That being said though.....I'd love to try a steeper gear and some real slicks to see what it would do:nice:
 
yea i came up wit the same price for the unit in unlimited mustang book. How does the car feel though with the 8 inch open?

Well lets just say it gets overpowered very easily.

i was talking to a drag racer on another forum, based on a lets say 14 sec run @100 in the qtr with a 3.00 open like mine. You could take off up to .5 sec with a gear and locker swap. thats a significant difference.
 
Don't buy those crap LSDs from the guys on ebay. They take normal old open diffs and "convert" them to LSDs. They are junk.

Save your pennies and get yourself a TruTrac. It is the cat's ass. No maintanence, no clunking, fast lockup.

I would guess that with the power you are going to make the posi, some gears, traction bars, and some good drag radials will pick you up more like 1-1.5 seconds in the quarter when you can get traction.

Good luck...

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Another option is to keep an eye out for a narrow 9" housing and get the T-Lok separately like I did. I don't think there is any more than $600 in the whole 1957 9" rear end under my '68. If you find a 28 spline T-lok and a small bearing housing, you can keep the axles and brakes from your Mustang.
 
I have a C4 and have been running 3.55's in my 8" for the last 11 years and GFG Drag Radials. No problems so far.
How does it cruise on the freeway with your combination. What rpm are you at doing 80mph. I was wondering if I should go 3.55s or like the 3.26 in mine. Do you guys know if a 94 mustang 8.8 will bolt right into a 67? how much wider or narrower is it?
 
How does it cruise on the freeway with your combination. What rpm are you at doing 80mph. I was wondering if I should go 3.55s or like the 3.26 in mine. Do you guys know if a 94 mustang 8.8 will bolt right into a 67? how much wider or narrower is it?

At 80? Man at 70 I'm at anywhere from 3,000-3,500 RPM. I do as little highway driving as I can and you will always find me in the farthest right hand lane.
If your going to be on the highway a lot, then a 3.25 will better fit the bill.
I am not sure about a 94 8.8 fitting?? It might work. I know the Fax body rearends will work in the 67-68 body styles with some perch repositioning.
 
My falcon only made 301rwhp and all it took was one launch on some old 26x10 et drags dumping the clutch at 3500 with a t5 to snap the driver's side stock axle and tear up the seals along with it.

I would at least try some mosers if you plan on racing it with slicks.