I have been desiding weither to use an 8.8 or 9" rear end. I am planning on running sumthing like 5.67 gears which i can get for both, but i have been told to run an 8.8 just because it will weight less and rob less power from my pp running some nitrous, thanks,Mike

 

I say the 9" bigger is better! --sarcasm

The description is a bit vague to get a constructive answer, what car? what application? Sounds like a FB/FC drag car? How many HP are you putting down? More details please!

 

ohh oops i forgot that lol its going into a rx3 with a custom 4 link, will be autocrossed a bit mostly drag, a weekend type car, hoping to weight around 2000 or less, the rear will be mostly tub'd, but will still have interior(fibreglass seats ,ect.) 12a MFR PP with 4 accel super coils, 2 accel 300+ with rev limiter, lightened rotors eshaft and flywheel, dual disk clutch, should be putting down around 280 before nitrous, thanks ,mike

 

Let the axle selection help you decide. Sometimes finding the right axle for an 8.8 is a little scarce. 9's are pletiful and sometime less expensive. To help with the weight loss, you can get a Aluminum thirdmember and a billet aluminum pinion support.

 

an aluminium third member and pinion support would cost wayyy to much money

 

A 9" is beyond overkill for your application. Not only is it unneccessary, but robs more hp than almost any other rear end due to it's extremely offset pinion gear. An 8.8 would be great but if you want a drop out center section like the 9", go with an 8 3/4" from a Mopar.

 

what about a dana 44??

 

I picked up a Mustang 8.8" complete rear (stock with posi) for $50 when I was going to put an upgraded rear in a project car. They are plentiful and cheap. Throw a good LSD in there with 31 spline aftermarket axles ($219) and new gears $150 and call it day. If you need to narrow the rear you can easily get narrowed axles. You can also do away with the C-clip eliminators by have 9" axle tube ends welded on. You can also get put Ford Explorer factory 31 spline axles as a cheaper alternative but they won't be a strong as aftermarket ones.

9" in your little RX-3 is total overkill and will weigh considerably more. Parts are expensive too.

Have you looked into putting a Toyota truck rear end out back (stock they have 31 spline axles and are stout). A friend of mine has a 600hp+ Buick GN engine in his Toyota truck that runs 10.0's@130mph+ and has yet to break it. Stock Toyota guts in the rear end and he is launching off a Tranbraked TH400 pulling the front tire way off the ground. Been racing it for years.

 

What is wrong with the stock rear end?? Is there some weekness you are trying to over come???

 

as for that toyota truck rear end what kind of gears can you get because the biggest i have found for the mopar and 8.8 is 4.88's and that is too little i need somthing like 5.67's

 

was the toyota a 7.5 or 7.8 rear end?? because you can get 5.71 gears for them which is perfect for what i want

 

or possibly an 8

 

if your really trying to build somthing to last put the 9" in there ..8.8 dont rob as much power but youll only have to put the 9" in there once