Need Advice:

[Mr 5 0]

Originally posted by mustardjohn :

Mr. 5.0

Do you just buy the ring and pinion 3.73 gear set and it fits into existing housing or is there more to it? The gear sets sell for about $168 before tax and shipping. Sounds like this might be a very inexpensive mod. Actually less than true dual exhaust kits including installation costs.

How significant is the impact on gas consumption say crusing at 70 mph on interstate?

The ring and pinion gears can be bought as a kit, with all the necessary hardware for installation. You'll need to replace the speedo gear and the axle oil and I recommend using synthetic gear oil when you do that. Prices vary. Check with a Ford Racing dealer or the Mustang magazine ads for exact pricing. I was guessing as I bought my rear gears some years ago and prices change. Leave the installation to a pro. It's worth the cost.

Going from a 3.27 to a 3.73 final ratio will probably decrease highway gas mileage by a gallon or two, maybe three. RPM's at 70 MPH will increase about 300 to 400. However, the 'seat-of-the-pants dyno' will register a very noticable improvement, especially at the low-end.