Differential !!!!
 

I have been reading here lately about breakage probs with the 31 spline Trac-loc. If this is junk then what does everybody recommend??? I am shopping now so any help would be appreciated. I am not looking for a locker or spool I want something street friendly but that will take the abuse of a blown 302 and will still stay together for the blown 347. Oh and slicks and aggressive driving will also be included in this TIA

blown 347 is NOT a good idea.

Is your car a 5spd? I use a 28spl rear trak-lok and go 1.58 60ft . If you do alot of street driving spend the $ and use a Detriot-Locker. Maybe its just my luck, I like the Trak-lok units,just repack the clutch plates 6 instead of 8

Why isn't a blown 347 good? there is quite a few out there and running fast without problems.

rich I have a 5-speed also the stock 28-spline axles with the extra clutches in it. I just can't run a slick because I know I will snap the axles with a hard launch. What kind of power are you putting to the ground and what is the setup to get 1.58 short times?? I know a guy running 1.6's but he has a stock stang with ET drags. The detroit locker isn't good for the street, I know of one fellow who crashed his car because of locking up and loosing control. The wife may drive this car so it must be drivable..

I have a Detroit Locker in my car and it works beautifully. Sometimes it does lock up rough and clinks going very slow around really tight corners. However, it is not as bad as everyone thinks. One time mine locked up coming out of a corner and my tires broke loose and i almost crashed. This is only because i was going a little too fast and there were loose cinders everwhere. Otherwise it works fine. I used to have an Auburn unit and the Detroit is ten times better.

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91 LX: Green/white stripes, cam, roller rockers, underdrive pulleys, K&N, full length headers, high flow H-pipe, Flowmaster mufflers, other little engine mods, and some suspension work

I'm curious, who makes a Detroit Locker for the 8.8 rear?

Stroking an engine puts a lot of stress on it. Supercharging one does as well. If you plan on driving this thing on roads (eg, it isn't just a track car), its just not a good idea. I guess maybe with a girdle, but I don't think its to good on a 2bolt. Maybe skyman or unit can say something more....

I understand what you are talking about with overpowering the block, or I assume that is what you are talking about. I got a sportsman block in the mail thursday, and will build this with forged internals and a girdle so breakage is not a concern for me. I doubt I will hit that much power. Keeping boost reasonable also, I like to be conservative so I can keep racing longer.

Detroit Locker is made by Tractech Inc. I ordered mine through my local speed shop who also installed the unit.

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91 LX: Green/white stripes, cam, roller rockers, underdrive pulleys, K&N, full length headers, high flow H-pipe, Flowmaster mufflers, other little engine mods, and some suspension work

OH! OK! Using a sportsman block, everything will be fine, I though you were talking about a stock block. I don't know how much boost you can run, but with a sportsman you should be ok. Get good internals too.

1.58 short times are with a 8" converter c-4 set up it is a mild 347. The good thing about the trak-loks is that they are rebuildable. A friend has a 302 5spd with a S- trim and goes through a set of spider gears a year, the rear works well, you should look at the diff at least once a year, and his wife could drive it ,if he would let her!

hey man sorry to cut in on your post but i was just wondering will bad spider gears cause a vibration? mine have a few teeth chiped of from them. i get the vibration at higer speeds it kind of feels like it only does this this on a half revolution of turning.
thanks

Broken spider gears are bad and could cause a vibration,there is a place in Penn. that has 31spl Trak-lok take-outs for $195 Explorer diffs, If the stock driveshaft has a lot of miles on it use the Motorsport aluminum shaft, good part and great price! The add for the rear was in MM+FFs.

thanks for the info on the better price.