I have a 1998 Mustang Gt with a 5-speed transmission and 3.73 rearend gears. What range is the best for power? Low end, middle range or High end? Can I burn the tires easily? As you can tell I am new at this speed thing, but I am willing to learn!

Well I'm no exspert but pretty well versed, I have a 3:73 in my '34 truck, but if you really want to get hairy and you don't mind the gas mileage get a set of 4:11's, I say stick with the 3:73's, they are a good rear, just build your engine and later if you really can't do much else to the engine and you want more hair on that stallion, a bit of giddyup swap to the 4:11's. the 3:73's are about best for just a daily driver/midnight streetlight tach. racer.

I may be able to offer you assistance with understanding the capabilities of the 1998 GT as well as choosing the correct gear.

We use a computer based automotive performance calculator that accurately reports the performance of a car based on user input.

I had the same question when swapping out the rear gear in my 1969 Charger R/T. I had a choice of 3.23, 3.55 or 3.91. The 3.23 offered the best 1/4 mile times and the 3.91 was 1 tenth slower in the 1/4 mile. The 3.55 was 6 hundredths on a second slower than the 3.23 and turned out to be easier to get.

For a street driven car the 3.55 gears were fine and I was willing to give up the 6 hundredths of a second quicker in the quarter.

We used our computer program PC HOTROD to help make these comparisons and were satisfied with this decision. The car ran great!

<a href="http://www.pchotrod.com" target="_blank">www.pchotrod.com</a>

Not all cars lend themselves to a 4.11 rear gear; other things come into play as well.

A 4.11 gear may feel faster (seat of the pants) but the end result relies on the total combination and may end up being slower and becoming a waste of money and time.

I ran the numbers on your Stang and the reports indicate the following:

Stock Trim with a 3.27 gear:
14.87 @ 93.1 mph & 0-60 mph in 6.3 seconds.
Top Speed 141.1 mph.

Stock Trim with a 2.73 gear:
14.86 @ 92.4 mph & 0-60 mph in 6.4 seconds.
Top Speed 142.8 mph.

Stock Trim with a 3.73 gear:
15.01 @ 92.4 mph & 0-60 mph in 6.7 seconds.
Top Speed 143.3 mph.

The 3.27 & 2.73 were installed by Ford based upon if the car was an automatic or a manual and I don't know which belongs with which so I ran the number on both as a 5 speed unit. As you can see the 3.73 does not help at all.

Ford did not offer a 3.73 gear as an option for the 1998 GT's. Are you certain that is what you have or do you know that it was swapped out to an aftermarket gear?

I can email you these report to you if you wish.

Visit our website to view the performance reports of other Hotrods.