You don’t have to convert all the numbers in a particular adventure beforehand. Using this equation allows you to convert statistics on the fly.
For example, a MasterBook value of 14 becomes a D6 code of 4D+2 (14/3 = 4, remainder 2). The quotient becomes the D6 die code and the remainder becomes the number of pips. The conversion involves one simple formula: divide the MasterBook value by three. If something doesn’t look right after you convert it, alter the value or die code to what seems more realistic.
Of course, since the conversion translates logarithmic values to linear values, you have to exercise good judgment. This system converts MasterBook characters and adventures to the D6 System rules (used in other roleplaying games produced by West End). West End Games: Masterbook/D6 System Conversion