GhettoRacingKid said:
I am putting a 700r4 and a 350 with about 400hp, using street tires. I just want the power to hit every once and while.
9 inch Rear/Original Rear
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I am putting a 700r4 and a 350 with about 400hp, using street tires. I just want the power to hit every once and while.
IMO youll be fine with a 7.5 if you wanna spend the money on a 9" or a built 8.5 you can its your choice.
I will be building a 7.5" 10 bolt rear for my Regal. My combo should have 400-425hp at the crank. I am not the least bit worried about a small 10 bolt build to lay the power down. I will pick up an extra rear from somewhere and completely build that one while still being able to drive around on the old one (well once its running :lol: ) my plans have just over $1,000 in parts alone for the rear end 8)
The only problem with an 8.5" is that everyone thinks they are worth their weight in gold. Its so expensive to even get an open carrier GBody 10 bolt 8.5" rear. I wouldn't mind going with an 8.5" ... but IMO, a used rear end is a CORE and a core is not worth $500 :idea: Unless mileage can be absolutely verified (which is about impossible with a GBody, since there was no hundred thousandths digit on the odometer) then it has to be treated like any engine someone would purchase for a rebuild
The only problem with an 8.5" is that everyone thinks they are worth their weight in gold. Its so expensive to even get an open carrier GBody 10 bolt 8.5" rear. I wouldn't mind going with an 8.5" ... but IMO, a used rear end is a CORE and a core is not worth $500 :idea: Unless mileage can be absolutely verified (which is about impossible with a GBody, since there was no hundred thousandths digit on the odometer) then it has to be treated like any engine someone would purchase for a rebuild
all depends on what you want to spend.
you can get a 28 spline posi unit and use stock 28 spline axle and stay on the cheap side or your can go crazy with the posi unit, axles etc....
you can get a 28 spline posi unit and use stock 28 spline axle and stay on the cheap side or your can go crazy with the posi unit, axles etc....
I'll be using MOSER axles and c-clip eliminators. I think I'll be using the Powertrax by Richmond No-Slip Traction System. One of our rebuild kits and Royal Purple fluid1979Calais said:
GhettoRacingKid said:
So where is a good place to buy the 28 spline posi unit and posi unit axles? Can I repbuild the rear on my own?
it depends on a combo of "power-level" and "intended-use"
in the 300-400hp range, you are looking at the upper limits of a 7.5 in stock form. An 8.5 will take that kinda power in stock form. A GM 12 bolt is good for 500-600hp in stock from. A ford 9" is overkill, you're looking at strict track use or high 600-700hp to justify this rearend.
so, strictly cost-saving purpose, a 7.5 is good for your application. But since you're looking at a rowdy street motor, you're gonna be on the upper limits of what a stock 7.5 can be trusted with.
the trick here is to avoid perfect traction off the line at full throttle. You're good with street tires as they'll likely slip coming off the line. You want to avoid full throttle launches with slicks or drag radials.
a posi is way more fun and great for traction, but an open carrier is fine for street use. If you want to ensure it stands up to the abuse, a rebuild will go a long way. And a studded girdle cover is great.
in the 300-400hp range, you are looking at the upper limits of a 7.5 in stock form. An 8.5 will take that kinda power in stock form. A GM 12 bolt is good for 500-600hp in stock from. A ford 9" is overkill, you're looking at strict track use or high 600-700hp to justify this rearend.
so, strictly cost-saving purpose, a 7.5 is good for your application. But since you're looking at a rowdy street motor, you're gonna be on the upper limits of what a stock 7.5 can be trusted with.
the trick here is to avoid perfect traction off the line at full throttle. You're good with street tires as they'll likely slip coming off the line. You want to avoid full throttle launches with slicks or drag radials.
a posi is way more fun and great for traction, but an open carrier is fine for street use. If you want to ensure it stands up to the abuse, a rebuild will go a long way. And a studded girdle cover is great.
Rebuilding a rear can be done on your own, but there is a very strict attention to detail when it comes to putting them together. It requires precise angle and clearance measurements throughout. I would make friends with somebody that has successfully built a rear end and have them present during the rebuild.
As far as where to buy these parts ... Your local NAPA can get everything you need. If your local bussiness is too proud of their merchandise, you can use SummitRacing or JEGS (or many other online vendors available)
As far as where to buy these parts ... Your local NAPA can get everything you need. If your local bussiness is too proud of their merchandise, you can use SummitRacing or JEGS (or many other online vendors available)
I prefer posi's so if I had kept the 7.5 I would have gone with a powertrax locker and 28 spline axles. The pinion gears in a 7.5 posi carrier are small and can't handle much abuse. I know this from experience. I wanted a wider rear end and one that can easily handle the power I have so I went with another rear but the 7.5 rear was an excellent rear end when used for it's intended purpose.
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