[WAC66stang]

Hey everybody, I was wondering what size rims a stock 1966 mustang came with. I currently have some 14" cragar s/s rims on my car now and they are pretty beat up from the rust. I found another set of the same rim online but they are 15" rims. Would the one inch difference screw anything up on the car?(speedometer, odometer, transmission?) I don't really know too much about this kind of stuff but any help from you guys would be much appreciated. Thanks for the help and let me know if you have any suggestions.

Bill

[astumpf]

you could put 15's on w/out screwing ur stuff up. since you are going to put a 1" bigger wheel on, you have to adjust your sidewall size on ur tires. the total outside diameter has to stay the same for everything to remain constant.

[67GTSeattle]

Try this, link to tire calculator that will tell you if the new set up will maintain the same rolling diameter.

Tire size calculator

[snaranjo]

If you can't keep the same tire diameter you can always install a new speedometer gear.. Check out this website Speedometer Gear Selector

I'm running 17 inch rims on mine with 245/45/17 tires at 25.7 inch diameter. My T5 transmission has a 7 tooth gear and the rearend is 3.5. I have a 19 tooth speedo gear to keep the speedometer pretty accurate.

[WAC66stang]

Thanks for the help everybody.