Rear End Setup

[Sturg]

So what is everyone's opinions on a 7.5 vs an 8.8? I was thinking about just getting a 3.73 gear for my 7.5... The car will eventually see a little drag racing but really its just meant as a nice car to cruise in.

[FM2NOTCH]

money spent on a 8.8 would be a wise investment. I spent money on a 4.10 gear for my 7.5 and broke it first pass on some sticky tires.

[82GTforME]

money spent on a 8.8 would be a wise investment. I spent money on a 4.10 gear for my 7.5 and broke it first pass on some sticky tires.

I had 4.10 in mine. I didn't race at the track, but the clutches inside blew apart eventually. I am upgrading now to an 8.8.

Launching and speed shifting could mean a quick failure for a 7.5 depending how many HP you're putting through it.

[Sturg]

This car won't see much horsepower for awhile...

[bwguardian]

If this is in a 85 it is an easy swap. The 8.8 unit will fit and bolt up...even the quad shocks...in a straight forward fashion. The only thing you might want to study a little prior to proceeding is the brake line braket/junction just off center on the drivers side. This braket is a little different link between the transition years of 85 and 86.

Personally I would not put money into a 7.5 unit unless you just can't find a 8.8 to utilize. Most 8.8's are going to cost you about the same money as the gear change anyways so why not.

[Sturg]

The car is an 85, I know the swap is straightforward I just don't know exactly what to look for in an 8.8, just make sure it's a track loc unit and that it is for 28 spline axles right? also is there anything to really look out for?

[Ethyl Cat]

The car is an 85, I know the swap is straightforward I just don't know exactly what to look for in an 8.8, just make sure it's a track loc unit and that it is for 28 spline axles right? also is there anything to really look out for?

Learn how to read the tag bolted to the rear end cover. I am sure there are articles on this site. It will tell you everything you need to know about a rear end if it is still there.

[bwguardian]

More than likely the unit should come complete from drum to drum. I guess you might find one from rotor to rotor if out of a T-Bird it that is the direction you want to go. I would check for the braket I mentioned above but more than likely the rubber hose is shot anyways and will need to be replaced which I would suggest anyways since the brake fluid eats them up from the inside out. You definately want a traction lock unit and may can even find one out of an automatic like I did that has the 3:27 gear in it.

[Sturg]

I can find just the 8.8 and put it in place of the 7.5 can't I?

[Chris Wood]

yep the 8.8" will bolt right in. If I were you, I would go ahead and replace the clutches in the diff before you put it in.

[Sturg]

I was thinking about just finding an 8.8 and getting everything freshened up and then throwing it in.

What's a decent price for a used 8.8?

[Sturg]

Also another question is about the axles... will an 8.8 work with 28 spline axles? or do I need to get 31 spline axles?

[82GTforME]

If you can find the right donor car at a junk yard, go for it! This is the one I bought. You probably want to keep the rear drums I'm assuming though. This was cheaper and easier than finding a decent core (honestly not as easy as you would think around me) and rebuilding one the way I wanted (Cobra set up). I do not have it in the car yet though. The front is being done first.

http://www.ebay.ca/itm/130495417378?...84.m1438.l2649

[Sturg]

If you can find the right donor car at a junk yard, go for it! This is the one I bought. You probably want to keep the rear drums I'm assuming though. This was cheaper and easier than finding a decent core (honestly not as easy as you would think around me) and rebuilding one the way I wanted (Cobra set up). I do not have it in the car yet though. The front is being done first.

http://www.ebay.ca/itm/130495417378?...84.m1438.l2649

Yeah, I'm going to keep the drums for now... I honestly will probably find a solid 8.8 throw some gears in it and swap it in... Just need to know if the stock axles will work in the 8.8

[LilRed86coupe]

I just bought a complete drum to drum 3.73 geared 8.8 for $250. It had repacked carbon fiber clutches also. Deals are out there,just gotta search. And yes,the stock 28 spline 7.5 axles will work in an 8.8,there the same axles. The 7.5's weak link is it's smaller spyder gears than the 8.8's. The two 7.5's that i blew up had Moser axles,repacked clutches and 4.10 gears. Both blew out the spyder gears on slicks dumping the clutch at 5k.