I found this info in another thread (for those wondering about the 62mm SC pulley) :

Based on 155mm, the crank pulley equivalent of a 62mm SC pulley is:

155 * 6200 = 62 * Srpm
Srpm = 15,500

Cd * 6200 = 74 * 15500
Cd = 185.0mm

Therefore, using the same calculation logic:

A 60mm SC pulley is equivalent to 191.2mm crank
A 61mm SC pulley is equivalent to 188.0mm crank
A 62mm SC pulley is equivalent to 185.0mm crank
A 63mm SC pulley is equivalent to 182.1mm crank
A 64mm SC pulley is equivalent to 179.2mm crank
A 65mm SC pulley is equivalent to 176.5mm crank

A 74mm SC pulley is equivalent to 155.0mm crank

More good reading here: https://www.crossfireforum.org/forum...ification.html