ok i was thinking last night that i was able to get my dodge up to 120mph from time to time the ford im putting my cummins in has a speedometer that maxes out at 85mph what happens when i eccede 85?

 

the needle stops at 85. will not go any higher.

my 86 tops out at 105mph. had a buddy follow me in his dodge gasser.

speedo goes to 85 and stops there. if u break the tab off it will keep rotating around.

 

really but it wont screw the speedometer up?

 

nope.

 

well cool deal one less thing to worry about

 

I'm pretty sure it's a magnetic deal in the speedo head, so there is no solid contact to break by overspinning it. I know the 80-86 trucks were magnetic anyway, and we know how lazy ford was when it came to upgrading some things.

 

this truck has a cable coming out of the cab im guessing is for the speedometer