cmayna,
Thanks for the info. With the original 4-speed transmission, my '59 Apache was geared too low even for around town. I had 3:38 gears installed in the rear end rear end, knowing the speedo was going to be off. After reading your post this am, I got the Speed Box app or my iPhone. Called Jim at PATC Transmissions...he wanted speedo readings at true speeds of 40, 50 and 60. Didn't really enjoy going 73 mph on I-680, but got numbers and called them back in to Jim. I have have an adapter enroute.
Again, thanks or the post.
Bob

1959 Chevy Apache Short Bed Step Side
1967 Cadillac DeVille Convertible
1967 Pontiac Firebird Convertible