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Author Topic:   7.5 Rear End
DEEDDUDE
Dirt Full Roller

Total posts: 56
posted January 02, 2001 07:38 PM
Anyone using a stock metric 7.5 rear end in their street stock? If so, What modifications did you have to do, to make it hold up on the track?

Pickel
Dirt Freak

Total posts: 239
posted January 03, 2001 08:56 AM UIN: 25419780
I dont know if this will help but I run an 8.5 rear end in my car..it works well..I did order a 538 gear for it five years ago and it still look new..I have broke 3 axles in 12 years of racein (do to contact with wall)but it I do carry spares.. The rear end I use is out of a nova/ camaro

[This message has been edited by Pickel (edited January 03, 2001).]

PEDDLER
Dirt Maniac

Total posts: 148
posted January 03, 2001 06:58 PM
DEEDUDE:
The 7.5 rear is a very light rear end. The 8.5 is much better,bigger brgs,bigger axles etc. The best bet is a 9 in from a Ford.
You can always change mountings. I had a 9in from a 68 Torino in a 82 Cutlass and put rear disc brakes on it using the same calipers as on the Cutlass front.

Find you a FORD 9in.

Pickel
Dirt Freak

Total posts: 239
posted January 03, 2001 07:42 PM UIN: 25419780
I agree the Ford 9 inch is better but when you can't afford the gears you run what you have. Watch track rules..some tracks you aren't allowed to run a Ford 9 inch on a street stock or a pure stock. (well on a GM car)

PEDDLER
Dirt Maniac

Total posts: 148
posted January 04, 2001 06:33 PM
Pickel:
I understand that some tracks won't allow a 9in Ford, therefore a GM 8.5 is a better choice. The gear option is limited, but its a good rear end.

DEEDDUDE
Dirt Full Roller

Total posts: 56
posted January 04, 2001 07:24 PM
Thanks guys. I would love to run the 9" ford, but rules state GM in GM cars. I looked at the 8.5" but I would have to get another trans. I have two 7.5" with the gear that I need. I was told that there are a few guys running the 7.5" with a lot of luck. I would like to know what their using. Aftermarket axles, bearings etc.. Thanks for your help. Deed

skawldeddawg
Dirt Roller

Total posts: 9
posted January 04, 2001 09:29 PM
there's an old boy that runs down at the track that i will be running next year.(1st year in street stocks,2 yrs in factory stocks),that is running a light GM rear end, and he said something about deep-freezing the axles? I don't know much about it,so i've been asking everybody(about rear-ends). The Ford 9" is the overwhelming favorite, I'm told because of their strength,ease of changing gears,and availabilty.Good luck!

johnss27
Dirt Roller

Total posts: 6
posted January 04, 2001 10:02 PM UIN: 26380308
if you are good what you can do is use the 7.5 rear end and install the ford type axels in it.they are the same 28 splines(size etc.) but you will need to cut the ends off and weld the ford end on the 7.5 . get the right length axels and use the ford axel.
you are still gm rear in a gm car.
the gears are ok but the axels stink in a 7.5 they are so small at the bearing and will break.

kong
Dirt Roller

Total posts: 23
posted January 05, 2001 10:23 AM
I ran in a class last year that required the 7.5 10 bolt. Some of the things the veterans recomended were to change out the axles with new ones at least every year. We used junkyard ones but we requested low milage ones. I know, it's a guess, but we looked at the bearing wear surface and choose the ones with little or no wear showing. Only use axles from the same side as the one you are replacing. In other words, if you break a right side axle, replace it with one that ran on the right side. Has to do with the twisting axles receive. Check your spool piece often, we broke two in two years. Try and overfill the pumkin as much as you can. If you take a hit hard enough to dent a rear rim, change out that axle just in case. These rears can survive, it just requires more maintainence. Oh yea, I only knew one guy that ran aftermarket axles and he said they didn't last any longer than stock, but I don't know how he drove either.

Pickel
Dirt Freak

Total posts: 239
posted January 05, 2001 11:13 AM UIN: 25419780
I know what your saing about the limit on the gears but my 538 seems to be ok at most tracks.. I would love to run a 9in ford but lack of funds for the gear is my prolem..lol

widebody
Dirt Full Roller

Total posts: 74
posted January 05, 2001 01:21 PM
The 7.5 are ok if they are checked all the times. The axles will twist. Use some old drag racing tricks. before you put the axle shafts in draw a line on them from the flange to the splines. When you check it you'll know right away if its twisted, but not broke. Youll be suprised how much they'll twist before breaking. Also pull out the factory plastic vent, and tap the hole for pipe thread and use a pipe-barbed end and clamp your vent hose on it, this is good for 2 reasons, it moves the vent higher so it wont leak/pump fluid out and it gives you a way to over fill it. Just stick a little funnel on the hose.
On a side note: the 7.5s are lighter, a few local IMCA guys run them with no problems, but the whole car is lighter.
For stockers I like the 8.5, easier on maintance.

34Racing
Dirt Full Roller

Total posts: 42
posted January 05, 2001 06:49 PM
Hey Deeddude I run a 7.5 in my 79 Buick Regal. I ran a 2.29 gear with the transmission in low gear. I didn't have any problems with my rear-end the whole year but I know that the bigger rear-ends are better. I'm trying to find a 8.5 or a Ford 9" that will fit my car. If anyone knows what model cars will work please help me out.

awkwardjeff
Dirt Freak

Total posts: 218
posted January 05, 2001 11:48 PM
34 racing, can you run floating axles? If so I got a 60 inch hub flange to hub flange...
complete axles, brakes, calipars are about 4 nights old................straight and complete $400...........email me If you cana use it.........Jeff

Pickel
Dirt Freak

Total posts: 239
posted January 16, 2001 08:31 PM UIN: 25419780
I forgot to ask you if you are allowed to run disc brakes? If so let me know and I will tell you how to make them cheap.

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