would 23 kill my overdrive
 

I have 373 in my 72 and was wondering should I just put the twentys on there or some 23, how would 20 work with 700r and 373 (275/45/20)other (285/45/23)

Re: would 23 kill my overdrive
 

What was the overall height of your tires before vs. with those rubber bands?

If it's no different, then it won't affect your overdrive.

If the wheel/tire combo is slightly larger, it will actually reduce your rpm on the highway. If they are smaller, it will increase your rpm.

EDIT: most important to remember, it doesn't matter what size rims you have. It's all about the overall height of the tire/rim combo.

Re: would 23 kill my overdrive
 

Wow, I love big rims and big tires just as much as the next guy, but I would have to have more rubber between the rim and the road than that. :) JMO ..............................Bamm!

Re: would 23 kill my overdrive
 

The tires on my truck are 235/75R15 which are 28.88" tall.

I found this neat chart online. It only shows a 31.41 and 32.61" tire for the 23" rims. Considering lots of people run 31" tires on 4x4's, even modern trucks, I don't see why it would hurt anything?

http://www.sstire.com/tireheights.html

The other big question would be rear end ratio. If you have a 3.73 and OD I wouldn't worry about it. If you're running a 3.08 gear, with the larger tire, your truck may be lugging a bit.

Re: would 23 kill my overdrive
 

the pic of the 20's on the 72 has 255/35/20 on the the 275/45/20 are a lot thicker they used to be on my caprice that is why the tires are small

Re: would 23 kill my overdrive
 

here's a calulator. Just plug in wheel and tire size and it'ss give you MPH difference. http://www.miata.net/garage/tirecalc.html