> Ah, I don't think this is correct. On the way to and from Shasta I cruised
at
> about 4000 rpms in 5th gear with my speedo reading 90mph... I know it is
> closer to 80-85mph. I have a 3.9 rear end.
You've changed both the rear end ratio, and tire size. Both affect your speedo
reading, so you have to compensate for both.
Without a calculator of this sort it would be hard to figure out where you
should be, although I don't know how accurate this calculator is.......
>3200 rpms was 70mph with a 3.7 according to the old Road and Track articles
I have seen.
Ditto on the tire size. I believe the stock tire size was about 25.5" (?)
diameter. Approximately equivalent to todays 175/75/14 or 185/65/15.
If you are not comensating for that size difference from the size of the tire
you are currently using your speedo IS going to be reading too fast most
likely.
With .85 for 5th, 3.9 rear, and 185/65/15's (24.47" diam.) the calculator
shows 3024 rpm...........Maybe a bit low?
>Any comments, cause
> I really would like to know what speed I am traveling at! I have changed
the
> trans speedo gear, but my speedo is still wrong, probably due to having
been
> rebuilt with used parts.
> Greg Burrows
> 67 2000
!
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