First off where can I buy some nice gears 3. something for my 87 cougar and second, how much time and work would it take if I was to take the challenge to change it on my own? I have looked at what needs to be done and was just seeing if it is worth it and if I could actually do it in a decent time frame.
1, just about anywhere. any ford speed mag. tons of distributors out there. summit, ebay, buyford raceing, brothers,jegs etc....
2nd. its not a novice job. chances are if you are asking you are probably going to want somebody else to do it.
if i were you in your situation, i would look for an automatic turbo coupe rear and put that it, you get a better gearing, and disk brakes all in one shot. if you do install gears in your xr7, it should have a 8.8 in the car. get gears from ford racing, they would be the easiest to install because they have the same measurments as the stock gears so you probley wount have to shim at all to get it set rite. and as said before, its not a novice job, so if u do it yourself, take your time and read up on it. you may end up having to take it out again and re do it if it makes noise.
Yes, the evil backlash! I recommend not installing them yourself, because i did and it didn't last more than a month. ANd i did that 5 times. Then i just swapped the rear end and got an 8.8 with disc brakes and good gears. Changing gears isn't that hard though... get some lipstick or carbon paper and a magnetic gage thingy... the end.