So, I bought a used rear end out of an '01 GT because I knew these came with a 3.27 gear standard, and they are an inch wider than the stock rearend in my '95 GT. After installing the reared, I didn't get much of a chance to drive it because I ran into some tuneup type problems. Well, I finally got it running OK and have started driving it to and from work again (25 miles each way).
Now I realize the gears that were in the rear are not 3.27's!
I finally got the car back on jackstands and checked the # of turns of the driveshaft to 1 revolution of the wheel, and I believe this thing has 3.73's in it. This is about the highest gear I would have put in the car period, but I didn't want to have such a steep gear in a commuter car. I'm going to leave it in for now, but I'm worried about mileage. Right now, according to my stock speedo gears, I'm turning about 2400 rpm at what I believe to be 65-70 MPH (the speedo reads 90-100 give or take). I say 65 because, I'm not passing anyone, and sometimes I'm getting passed at this RPM.
I want to get my speedo re-calibrated, but I'm not sure which gears to get. The latemodel Resto site shows gears to use up to a 3.55, but not for 3.73's for my year. I'm thinking I'm going to have to replace the gear on the tailshaft as well, but if I do that, which speedometer gear should I use?
Looking back, there was newer silicone being used for the seal on the cover. I just assumed it had been serviced. I almost feel like calling the yard to see if they may be willing to swap rear ends, but I don't want to deal with it right now, I don't even know if they have another '01-'04 GT, and I know if I put a cam in the engine I want to build, it will need the gearing. The only thing I don't like about the gears (besides the drop in mileage...) is the lack of RPM range I have now. Stock 5.0's don't want to rev to 5000 rpm, and now the cruising rpm is higher, so it almost feels like I'm driving a diesel because I have less usable RPM where I do most of my driving.