This table can be used as a guide to selecting the appropriate curve for your particular application. Select either the standard engine specification, or if you have a distributor with a curve that works well already, you can read the Lucas service number from the side of the distributor body to match.

Service number 123/Mini curve Application
40767 C 848 Mini UK Vehicles Regular Fuel
40768 F 850 Mini
40774 3 997 Mini Cooper HC
40819 C Mini Cooper S Mk III, 1275 cc
40873 F 997 Mini Cooper LC
40899 C Minor, Van and Pickup, 1098 mini Low Compression
40931 4 Mini early including Wolseley Hornet and Riley Elf
40941 F 850 mini  Late Model High Compression
40955 F* 998 Mini Cooper High Compression
40958 F* 998 Mini Cooper LC and special order for low grade fuel
40979 B Works special for Rally Mini's
41007 C 848 Mini UK Vehicles Regular Fuel
41026 E 848 Mini UK Vehicles Premium Fuel
41030 0 Mini 1000 Saloon, clubman and Estate, 998 cc,
41031 F* 998 Mini Cooper LC
41032 F* 998 Mini Cooper HC, 1971-75 Morris Marina 1.8 TC
41033 E Mini Cooper S Mk III, 1275 cc
41045 A 998 mini Early Model High Compression
41057 B 998 mini Late Model High Compression
41134 A 850 and 998 Mini Automatic including Riley Elf and Wolseley Hornet, 1100 automatic
41212 B Mini 1000 and Mini Clubman, Saloon and variants, 998 cc,
41214 2 1275 non S Mini, Austin 1300 HC and automatic, Riley Kestrel 1000, Wolseley 1300 and Vanden Plas Princess 1300, MG 1300 Automatic
41242 A 850 and 998 Mini automatic, Vandel Plas Princess 1300 and Wolseley 1300 twin carb
41246 B Mini 1000 and Mini Clubman, Saloon and variants, 998 cc, 1972-74: Mini Clubman 1100, 1098 cc, Allegro 1100
41249 F Later Minis and Moke
41250 C Mini Moke, van and pickup, later models
41251 A 850 and 998 Mini Automatic including Wolseley Hornet and Riley Elf
41254 5 998 Mini 72 to 74 including Wolseley Hornet and Riley Elf
41255 D 998 Mini Cooper, late
41257 2 1275 non S Mini, Austin 1300 HC and automatic late
41404 0 998 Mini ( Canada ) 1975-80, 1974 onward Leyland (SA) 1.3 van, 1974-77 Morris Marina 1.3, 1975-78 Morris 1.3 HC
41410 4 1970-73 Austin 850 LC, 998 Mini automatic, 850 van and pickup, 1976-78  Morris Marina 1.8 GT and HL
41411 B Mini 850 Saloon and variants, 848 cc
41412 5 Austin 1000 Mini automatic and Clubman, 1975 Authi Mini 1000
41417 A 1969 Austin 850 Mini automatic, 1976-80 Austin 850 Mini, 1970-80 Austin 1000 Mini automatic, 1976-80 Austin 850 van and pickup, 1970-77 Austin 1100 Automatic,
41418 8 Mini 1000 and Mini Clubman, Saloon and variants, 998 cc, manual and auto, Allegro 1.1
41419 0 1970-80 1275 non S Mini, 1973-79 Austin Allegro 1300 HC,1969-74 Austin 1300 HC Automatic, 1970-74 Austin 1300 France, 1969-73 Austin 1300 Princess including automatic
41532 C 998 Mini ( Canada )
41569 F* Mini 850 Saloon and variants, 848 cc
41570 5 850 Mini, van and pickup
41858 B Minis with engine number 12HC18AA, 12HC19(AA), 12HD20(AA)  12HE41, 12HE42, 1984 onward Austin Metro 1.3 van, 1981 onward  Morris 440, 575 Van and Pickup 1.3
41882 4 Metro 998, Minis with engine number 99Hxx, 1988- onwards.
41938 D Minis with engine number 12HC09AA, 12HC10AA, 12HD14(AA) 12HD15(AA), 1983-84 Austin Metro 1.3 HLE
42535 2 Minis with engine number 12A2BG01,  12A2BG03, 12A2BG05.
42626 4 Minis with engine number 12HD09, 12HD10, 12HD11, 12HD12, 12HD13, 12HD21, 12HD22, 1984-86 Austin 1.3 L and HLE
42627 4 Minis with engine number 12HD17,  12HD24, 1986 onward 1.3 Vanden Plas, 1984 onward MG Metro
42628 7 Minis with engine number 12HD26(AA)  1984 onward MG Metro turbo
42630 A Minis with engine number 12HC17AA,  12HD18
42635 4 Minis with engine number 12HD25 
42681 6 Minis with engine number 12HE48, 12HE25

* These engines require more maximum advance than the 123/Mini can provide, but curve F should allow the engine to operate well.