8.8 swap: how much can 28 spline axles take?

Feb 11, 2007
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I am planning an 8.8 upgrade for my 66 mustang. I plan on swapping in a fox 8.8 with 5 lug 28 spline axles and rebuilding the stock trac lok. it has 2.73 gears in it now but i plan on upgrading to 3.55s later. The motor makes 450 horsepower and goes through a C4 automatic. It will be on street tires and rarely if ever on slicks for drag racing. I plan on taking it to the strip occasionally and, with 3100 pound weight of the car, plan for high 12s on sticky street tires. Will the factory 28 spline axles hold up? I already plan on c clip eliminators as a safety precaution. Is there another weak point to the factory 8.8 I should be aware of?


Future plans may call for a junkyard 31 spline upgrade, but I would like to have this rear in the car and not have to worry too much about it. and no, plase dont post telling me to go to a 9 inch. Its a sore subject trying to find one in northern IL
 
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the 8.8 28 spline unit will handle more than the c4 will be capable of itself.

i make it no secret that ford automatics suck in my opinion, particularly the c4, which was the worst of the worst. sure, they can be made to handle the power, but not cheaply. fords rear axle reputation was far superior to their automatics reputation.

id not hesitate to use a 100% stock 8.8 in your car. id personally take a 9" from a granada and use it, as i prefer the removable 3rd member for its ease of gear changes, but theres nothing weak about a street 8.8.
 
Just get hardened axles, when I swapped to a fox8.8 I put in Superior 28 spline axles. But I have heard alot of people with more than that power and still on stock axles, also since its a auto I thought they launch a lower rpm then say a t-5.

Just my 2 cents.
 
eventually plan on swapping in a T5 or tremec trans


again, just put it in stock and dont worry about it. if youre concerned, set aside a few hundred bucks just in case you want to order stronger axles later. but im betting that money will jsut sit there unused.

ive already voiced my opinion on the c4. that opinion is the same as for a t5. you'll break that garbage before you break an 8.8 too. when i wanted to convert my 86 GT from an AOD to a stick, the t5 wasnt even an option. simple fact is that they WILL break with any kind of performance usage. half of them would break behind a stock 5.0L. if you want a 5 speed, go for the tremec 3550 or go one step beyond and get the TKO and know youre safe for future hop ups. if you dont wanna drop $2K on a trans, youre lucky putting this in a first gen mustang....use a factory toploader setup like your car couldve come with. they can take some serious abuse.