64p is very close to Mod 0.4. I know 32p and Mod0.8 are close enough to work without any problems, but not sure if 64p/Mod0.4 are close enough to do the same since the teeth are much smaller and therefore more critical.
Here is a table showing the conversions between pitch and mod#:
Code:
Mod 1.5 = 16.92p
Mod 1.0 = 25.4p
Mod 0.8 = 31.75p
Mod 0.4 = 63.5p
32p = Mod 0.7938
48p = Mod 0.5292
64p = Mod 0.3968
Formulas:
mod# = 25.4 / pitch
pitch = 25.4 / mod#