I have an 06 GT drive shaft which has a flange on the transmission, a slip joint in the middle (center carrier bearing) and a CV joint at the pinion, so my setup is a little different than most swaps. I think the CV joint probably helps reduce vibration but other guys run u-joints and don't have problems.
Most guys that use u-joints replace the pinion flange with a yoke. This page has some good options, and they are about $50 each.
http://www.iedls.com/page10.html
I bought one but didn't use it (I sold it). The PY-8.8-1310 works with 1310 u-joints, which most vintage Mustangs used, and the PY-8.8-1350 is for 1350 u-joints which are larger and stronger. If I were having a driveshaft altered or made I'd get 1350 u-joints.
Basically the steps are:
1. Cut off the unused stuff - like the sway car mounts and the flange for the damper weight, trim the bosses around the ABS sensor. I also cut off the outer rim on the disk brake dust sheild so the whole rotor would be visible (more for looks than anything). I later welded nuts to the drive shaft to mount the break line components since they originally mount to the sway bar mounts.
2. Cut off the spring perches and move them to the new location, BUT you have to get the pinion angle right BEFORE welding the perches back on. I put the car on jackstands as level as I could get, measured the transmission angle (which is 3 deg down) and established a reference. I put the rear end on the springs, held loosely with the u-bolts, then jacked up the rear end to put full weight on the springs, adjusted the pinion angle to 3 deg UP and then tacked the perches to the rear end. Make sure the rear end is centered on the springs (measure from the axle flanges to the springs). I had to measure the angle with the rear end on the springs since it turns as the springs compress. I first set the angle and welded them up by measuring the rear end itself on jackstands. When I put it in the car it was down quite a bit. So, put it in the car and then measure against the car/transmission angle. After you tack them in place, drop the rear end and weld them up.
3. Change the pinion yoke, replacing the seal. You have to pull the axles and differential to get the pinion out anyway, so change the axle seals and check the bearings and trac-lock components (and clean and paint the rear end and brake stuff while it's apart).
When replacing the pinion yoke, get a new crush sleave from the dealer. That thing is hard to crush so you'll need something to hold the pinion tight. What I did was probably not the best (since Ford has a special tool to hold it). I removed the pin that holds the spider gears and put a breaker bar in the hole, then wedged that against the housing so the differential couldn't turn. It bent the bar and marred the differential a little but doesn't seem to have caused any problems. Check the manual for the preload torque before tightening the pinion.
Once it's all tight, put on the cover and seal it with RTV. Put in new oil and trac-lock lube.
4. Rebuild the brakes (if you're wise) and run the brake lines, welding nuts to the tubes to hold the brake lines.
5. Install it, connect the brake lines, drive shaft, tighten u-bolts, check pinion angle, blead the brakes, burn rubber.
The major issues I found were:
1. The pinion flange should be replaced with a yoke to reduce the size. I don't know if the stock drive shaft is the right length but in reading about other swaps nobody has mentioned modifying the drive shaft so it probably works as is (after putting a yoke on the pinion).
2. Since the pinion is offset about 3" to the passenger side, the yoke will be out of the tunnel a little bit. For a car that is not lowered, and has the flange changed to a yoke, that probably won't be much of a problem (provided the angles are right to avoid vibration). Since my car uses the 06 GT pinion CV flange, it is about 4" diameter and 3" long and is under the passenger floor pan. When I hit large bumps the thing would hit the floor pan. I cut a notch out of the floor pan - about 6" long and 5" wide and welded in a piece, shaped like 1/4 of a coffee can, so the CV flange wouldn't hit. Since I did that I haven't had any problems with it hitting the floor. I also moved the pinion snubber back so it hits the top of the housing (it does hit that now and then). I used a piece of 1" rectangular tubing (about 3" long) and welded that to the back of the pinion snubber mount and bolted the snubber to that. I can take a picture of that if it's not clear (as well as the notch in the floor pan), let me know.
Other guys who have had the yoke hit the floor just beat the area with a hammer and that made the difference. My pinion CV/yoke mess is huge so I had to do more than most have.
Given the length of the drive shaft (which I forget now) the angle calculates to about 3 deg each end for the pinion offset, so it should be within the acceptable range.
3. You have to cut off the spring perches and move them. I think the Mustang springs are on 43" centers (but check that - I can't find the info and I could be wrong). I just used an air-powered cutoff wheel and re-used the spring perches, or you can buy new ones from Summit (they are 3" so you'll need to massage them a little). The axle tubes are 3 1/4" diameter, so you will need larger u-bolts. I ordered the Explorer bolts from my Ford dealer and got robbed - $15 each ($60 for 4). I should have gone to the brake shop or O'Reilly's and got some generic ones. I re-drilled my stock spring pads/shock mount plates for the new holes and haven't had any problems. Some guys use the Explorer plates, reverse them (so the shock mount is on the front) and use late-model Mustang shocks (since the Explorer shock has a bolt eye instead of a stud on the lower end).
I cut some metal off of the metal bosses that protect the ABS sensor on top of the housing since this is where the snubber hits. Those were hitting all the time so I cut them off.
I also cut off the flange for mounting the damper (the large weight on the side of the pinion shaft area) so it wouldn't hit anything (like exhaust pipes). Mine are far enough away that it probably would be okay but I cut it off anyway - 30 seconds with a sawz-all.
4. For emergency brake cables, I bought the short side (left I think) Explorer cables and used a floor-mount handle from an 89 Mustang. This handle assembly doesn't have quite enough range to get the cables as tight as I would like (without the handle sticking straight up). You can see this on the cardomain page (if it ever works again). I will probably go back to the under-dash handle but have to figure out a cable mechanism and am too lazy right now.
My cardomain page (when cardomain is working, which it hasn't been lately) has most of my write-up. Here are some others:
http://forums.vintage-mustang.com/mo...-67-coupe.html
http://forums.vintage-mustang.com/mo...rearend-6.html
This article is about Mustang 8.8s, which use 28-spline axles, but some good info none the less.
http://www.carcraft.com/techarticles...end/index.html
Hope this helps. Any other questions, let me know or PM me.
