i currently have the 8in on my 67 coupe and am wondering how they stand up comaperd to the 9 in is it just a good or what i am not a big racer or anything but i do like to put my foot on the pedal and drive my baby hard from time to time just to get a thrill but would there be any advantage to having the 9in over the 8in cause its mainly a daily driver but i am gunna take it from 2.75 ratio to a 3.80 but only if the axle will fit my usage cause if it don't then i will get the nine

 

i assume you have like a 289 or something in your car....and if its a daily driver, a 8" is fine. a 9" is never a problem but isnt really needed for what you got going on.....

 

ok thats what i thought i just wanted the best for what i got and not over kill cause i don't know anything bout the 8in but i found out first hand that Dana 44 isn't good for 4WD and was wondering if i would have to change to a nine like i changed my truck to a Dana 60

 

what about an 8.8??

 

if u have the extra dough....and know how....the go for it....get posi and 3.25 or 3.50 gears while your at it....but if not....ur fine....get posi still though if possible lol

 

I would keep the open spool 8” as it will handle up to 300hp, and not go so steep on the gearing. Go with a 3:25 or 3:55 instead.

Going from a 2:75 to a 3:80 will drastically kill your gas mileage. An 8” rear gear from a performance company such as Auburn gear can handle up to 400hp.

Cheers…..[sm=icon_cheers.gif]

 

Agree on the ratio, 3.80 is a bit deep, I wouldnt go more than 3.55 and if its a daily driver a 2.79-3.00 would be perfect. The nice thing about an 8 or 9 is gear swaps are quick and easy. So if you wanted you could have a 3.80/4.11 pumpkin and a 2.70-3.23 gear for cruising.

An 8.8 gear swap is much more involved, and getting one under an early mustang takes more than just boltin it in

 

isnt a spool what they use for like striaght line drag racing....?? u cant even turn...its a 100% locked differential....?

 

ya i was thinkin bout it last night and the 3.55seems to be a better choice

 

a spool isnt a differential, as it it doesnt allow one wheel to turn faster or slower, yeah they are locked together. its a solid piece betwen both axles, no clutches, cones or anything. just a chunk of aluminum or steel with a ring gear mounting face, some bearing races, and axles splines. very light, very strong, and very race oriented.