I was wondering how i could tell how fast I have had my truck up too since my speedo stops at 100. I was on an old back road today near my house and I put it to the floor. Once i let off it took it a moment to drop back under 100 on the speedo. I have 3.73s, not sure of the tire height at this moment, but they are pretty standard size michelins. I let off around 4600 rpm so i was just curious how high it was. I was guessing around 110.

 

actually I just found a good site for this. http://www.mustangii.net/topspeed.asp

Im not sure about the height of my tires and Im pretty sure the rear gears are 3.73s so that would put it aroud 106-110. It actually felt faster than that. Me and my brother were surprised how long it took to come back down under 100.

 

Sounds right. But the engine just keeps on wanting to go doesn't it? Hee Hee!

 

I was surprised my truck still had some life left in it. I would say that on a LONG open stretch it would hit 120 or so. It was going to keep climbing past 4600 i could tell.

 

so what does 5600 rpm in 3rd gear, with 3.42's and 30.5" tires mean?

 

The calculator says 148.... hmmm, sounds about right, since the speedo took seriously 30 seconds to come back down to 120

 

http://www.smokemup.com/auto_math/index.php#3

This is a kick *** site.

 

That works out to better than 135 in my 4x4. I know it seemed like I was going fast, but not that fast.