An 050 is a Stock Distributor, it's counterpart the 250 is for Type IV engines. Both share the same characteristics: Timed ATDC instead of BTDC, Nearly 40 Degrees of total advance (Vacuum + Mechanical). Two vacuum ports (one for advance, one for retarding the advance). The 009 is straight mechanical with approx 22 degrees of advance and is timed BTDC.

The Confusion about the 050 as being high performance comes from part numbering scheme, many original 050 Styles were the 015, 117 and 215 (If memory serves correctly). The 050 and the 250 are replacements for these.