[NavyGuy]

Hey guys, I know this board may be for more "real" hot rods, like older ones from the 60's and 70's but I still want to hit you up for some info/help. I was approached by a friend to install new rearend components in his 93 mustang. It has an 8". Included in the parts I am to install is a posi-traction or semi posi-traction or something along those lines, anyway, it won't just be a simple change of ring and pinion and bearings. He is also changing gear ratio to 3:73 or somwhere close to that. Now I got an awesome article from another post abotu rebuilding a 9". Walks you through it step by step. SO is there anything out there that can help me with this: installing a posi unit and changing to bigger gears on the 8" ford? My expertise is under the hood work and have only limited experience in rearend work, but that is not to say I can't do this job either. There's not much mechanical I can't do with a little guidance the first time around. Any help or sites or articles you guys can provide would be great.

[farna]

The main thing you have to be concerned with is the ring and pinion setup. I'm reasonably sure the pinion gear is set the same way in the 8" and 9" Fords (crush spacer, IIRC). Get that right and everything else is a bolt in. If you have a dial indicator it's easy enough, but get some blue dye to check gear mesh pattern. Anything that will leave an easily discernable mark on the gears will work -- I've seen it done with just grease, but the blue stuff is easier to see and you're less likely to make a (costly) mistake. Speedway (www.speedwaymotors.com) sells a rear gear setup kit for under $100. Has dial indicator and necessary fittings, and in a plastic case. Most shops charge $150-$200 to setup the gears. If this is the only time you'll be doing a gear change I recommend you put everything together then get a shop to set the pinion up. If not set right the gears will wear out much faster and could grind themselves into oblivion in a few hundred miles.