I'm getting to the point in my sr swap where I should start thinking about the dash. I had kind of thought i'd just leave the sedan insert (I.E. not the round speedo) in but being mechanical I had thought that if I wound it off the end of the scale it would likely wreck it.
Anyone wrecked there mechanical speedo by going to fast?

It won't wreck it. There is no mechanical connection between the speedometer needle and the cable. It moves by induction and just stops when it gets all the way round.

Oh really cool. I didn't know that. So it will just hit the stop at 100mph and sit there until it comes back under 100mph?

might wreck your underpants though

it wont stop at 100, it will keep going round until facing straight down, then u need to work out the speed from the revs, doesnt hurt it tho.

Wont hurt a bit. My old man has an 79 corvette and it was marked 85mph needless to say every time he drove it it would see that mark. 15 years later and its still doing just that

haha when I first brought it I got the stock a12 to hit 100mph (just) that just about wrecked my underpants.
It sounded like the world was coming to an end with the noise it was making.
But I was passing a stock ke70 at the time, couldn't have that beating me now could I? :)

sounds like your speedometer is about 10% off

Could be, it was a bit of a down hill run and it certainly wasn't sitting at 100 mph. It was touch the 100 mph mark and back down to 60 because it sounded like the motor was going to explode if the car didn't try to rattle itself to pieces first :)