Rearend Rear end??????

[RITTER]

Just my opinion here ... I believe the FORD 9" is completely over kill for a primary street car. It robs more power than its worth. A correctly built 7.5" / 7.625" / 8.5" is fine for a street driven car. The launching on a drag strip is what is most prone to breaking a rear end. Lighting the tires up out on the street is not hard on a rear end :idea: With the use of good bearings, aftermarket axles and good C-clip eliminators ...

I know it'll probably start another rearend arguement, but I just honestly believe that the FORD 9" only purpose under a GBody is for drag racing. Don't get me wrong ... I would put one in my car if I got a killer deal on one

CHRIS.O had a Cutlass with an Olds 460ci big block and a built 7.5" 4.11 rearend behind it ... never had any issues, and it had been in 3 other cars down the drag strip before that car I know we all go off of personal experience and I have never seen a built 7.5" destroyed on the street.

 

[GhettoRacingKid]

in addition to what Ritter was just saying.

A 9" is overkill for the street. This applies to everything with the car. What are you going to do with the car? and What do you want it to be when its done.

I actually just placed my order for 9" from QuickPerformance. Cant wait for it come. I am going to be running at the track a lot. once in a while on the street and pushing some serious hp and should be dipping into the 9's in a season or 2.

I was running a 8.5 and loved it. Never changed anything. the 3.42s were good for the street and my set up. the 7.5 was junk and I spent the money on the 8.5 instead of investing money into the 7.5 since it was only temporary.

I have seen alot of people putting serious power behind a 7.5 and running for years.

but I have seen a buddy of mine bend his 8.5 axle tube but he was running a boosted 10.0 GN


point of the post.

What are your goals, What are your needs, Whats your budget

 

[pontiacgp]

I have no issues with the 7.5, we welded the side gears cause we couldn't run a spool at the circle track and never had a problem. The axles were the weak link so the right side axles were upgraded. The reason I went from the 7.5 to the 8.2 in my street car was because the spider gears in an Auburn posi blew and when I noticed the size difference between the pinion gears in an open 7.5 compared to the pinion gears in the Auburn I wouldn't trust the Auburn again so it either run an open rear or a locker. I wouldn't run an open and for a locker it wouldn't make sense not to upgrade the axles so it worked out cheaper for me to go with an 8.2. I wouldn't run a 9" cause they are too heavy for my needs and I like to get rid of sprung weight, not add to it but you can't beat a 9" if you are running massive power or you want to change your gear ratios, that 3rd member makes the job real easy.

 

[mhsmontels1]

My goal with my car is to keep it a street car but if I take it to the track I want to be noticed.... I haven't built my engine up yet to the horsepower I mentioned but I don't want to build up a weak rear end and then do some add ons to my engine then not be able to drive because I overloaded and broke the rear end! I feel like I am gonna go with the 8.5 GN Rear end because I can buy a housing and it's reputation is great and I hope I can keep the price close to 1,000. I want a rear end that gives me the stop then go feeling when I hammer on the gas!!!!!! If anyone on here knows where I can find parts the Grand National 8.5 rear end for cheap let me know!

 

[snowmangaggift]

can you buy just the differential? or do you have to buy the whole axle and everything? for example if you just wanted to change the gears

 

[mhsmontels1]

The only thing i have a chance to buy right now is a 8.5 housing

 

[85GPLef41]

The only thing i have a chance to buy right now is a 8.5 housing

then at least you know it will bolt in fine.... 30 spline Axles from Moser i believe are around $260, a 30 spline Eaton new posi under $500, girdle 150 and a proper rebuild kit 80 bucks or so should be fine..I am on that rebuild now on the cheap!!. bet you could find a standard 28 GN spline parts even cheaper! I bought some stock axles for 125 in good shape a while back. i'm in the process of rebuilding the 87 GN 8.5 rear and found the axles worn down... So whether i upgrade to 30 spline or keep it 28 spline it should still hold up to street use. :wink:

 

[mhsmontels1]

Thanks for the info 85GPLef41... If I have questions as I gather parts I probably will pm you on here.

 

[85GPLef41]

no prob! I am looking on what i need to collect to get it done... Though i'm sure most of the guys around here can also help out as well.

 

[Dugan]

I have a 9" housing for sale in new jersey hit me up