how fast with 7.5 rearend

[dt79]

like it says whats the fastest anyone's run with the 7.5. i have one thats a posi so i thought i might try it for a while. does it save any horsepower compared to the 8.8?

[White90GT]

Don't know for sure, I've heard of guys running bottom 11s on them, most likely with Autos. My cousin is installing some GT40 Y heads, exhaust, E303, weiand intake, 650 holley, and tuning. We're going to see how far we can push his 85GT with the stock 7.5 rear and stock gears with a stock T-5

[AnthonyDalrymple]

Originally Posted by White90GT

Don't know for sure, I've heard of guys running bottom 11s on them, most likely with Autos. My cousin is installing some GT40 Y heads, exhaust, E303, weiand intake, 650 holley, and tuning. We're going to see how far we can push his 85GT with the stock 7.5 rear and stock gears with a stock T-5

Same thing I've heard; but have not seen in person. I would think, just like using an 8" versus the more popular 9" rear diff in the "older days; the 8" get's the job done up to about 300rwhp. Probably the same situation with the 7.5 versus the 8.8" More power than that.... It becomes a crap shoot.

[MONTsterLW]

I was wondering the same thing. I have a 7.5 T/L rear out of an 86 Turbo Coupe I am going to install in my Futura to start out with. Later it will be replaced by a 9".
Unless I have been ill informed, aren't the axles the same as 8.8 axles? The units look kind of puny, but I am not putting drag radials or slicks on right away, so I am hoping it will give me a summer's worth of use.
Anyone who has beat on one of these things hard, please chime in!
Thanks- L.W.

[forsale]

Had one in my 83 gt DONT dump the clutch at 5,000 took off 5 teeth on the ring gear.

[red89coupe]

see sig.. I just added nitrous and it has taken the 75 shot with no problems so far It will be taking a 150 shot and we will see what happens but I think the reason mine wont break is beacuse I have a 8.8 ready to be swaped in when it does go

[red89coupe]

Originally Posted by MONTsterLW

I am hoping it will give me a summer's worth of use.
Anyone who has beat on one of these things hard, please chime in!
Thanks- L.W.

I have BEAT THE CRAP out of mine. it just seems to take it. I have broke 2 trannys,1 imput shaft and 1 second gear cluster but the 7.5 is fine so far. 100 timeslips,10,000 miles and 1000 miles of driving like I was trying to break it
I dont dump the clutch and I dont hook for crap with street tires. with STICKEY TIRES IT WILL BREAK.

[Speeds8erM-1]

Thats the main thing, if you put tires to it or dump the clutch alot, it WILL break fast! I come from F-Bodys, they come with a d@mn 7.5 stock and it's a JOKE with a stick shift. If you can keep the clutch or tires spinning it will last a little while, take the fusable link out of the equation and blam!

[Nick L]

I broke the one in my old ranger with a 2.9 busted every tooth of the ring gear.

[90 Crustang LX]

What gears came stock in the 7.5's?

[red89coupe]

Originally Posted by 90 Crustang LX

What gears came stock in the 7.5's?

3.45 came in mine and seems to be pretty common.

[onesillynotch]

they last a while if they dont have a trac-loc..

[red89coupe]

Originally Posted by onesillynotch

they last a while if they dont have a trac-loc..

I dont know
my trac-loc has seen many many passes and alot of street/highway miles. but I get NO traction,(2.1 60 foot ) NO dumping the clutch,NO crazy burnouts or anything like that.

now that I said that next time out its flying out the cover

[Rather B. Racin']

Running a 7.5 w 4.10s and lincoln locked its been bullet proof for several years now on slicks.