The 123\GB-4-R-V replaces most 4 cyl. Lucas-distributors for engines in Great-British (hence ‘GB’) cars.
Note that there are dedicated 123-ignitions for Mini, Jaguar & MG.
Please check if the distributor need a connection for a mechanical rev.counter, as a 123\GB-4-R-V does not offer this.The unit offers a maximum total of 16 advance-curves to be selected by the end-user.
Please take a look in the table below for available advance curves.
| curve | advance starts [rpm crankshaft] | max. advance [rpm] | [degr. crankshaft] | vac. adv. starts [mmHg] | max. vac. adv. [mmHg] | [degr.] | replaces | remark |
| 0 | 1000 | 4200 | 17 | 100 | 300 | 10 | LUCAS | 2000/5,0 |
| 1 | 1000 | 3600 | 17 | 100 | 300 | 10 | LUCAS | 2000/6,5 |
| 2 | 1000 | 3000 | 17 | 100 | 300 | 10 | LUCAS | 2000/8,4 |
| 3 | 1000 | 2500 | 17 | 100 | 300 | 10 | LUCAS | 2000/11,0 |
| 4 | 1000 | 4500 | 20 | 100 | 300 | 10 | LUCAS | 2000/6,0 |
| 5 | 1000 | 4500 | 20 | 100 | 300 | 10 | LUCAS | 2000/8,0 |
| 6 | 1000 | 4500 | 20 | 100 | 300 | 10 | LUCAS | 2000/10,0 |
| 7 | 1000 | 4500 | 20 | 100 | 300 | 10 | LUCAS | 2000/12,0 |
| 8 | 1000 | 4500 | 23 | 100 | 300 | 12 | LUCAS | 2000/6,5 |
| 9 | 1000 | 4500 | 23 | 100 | 300 | 12 | LUCAS | 2000/9,0 |
| A | 1000 | 4500 | 23 | 100 | 300 | 12 | LUCAS | 2000/11,0 |
| B | 1000 | 4500 | 23 | 100 | 300 | 12 | LUCAS | 2000/13,0 |
| C | 1000 | 4500 | 26 | 100 | 300 | 14 | LUCAS | 2000/7,5 |
| D | 1000 | 4500 | 26 | 100 | 300 | 14 | LUCAS | 2000/10,0 |
| E | 1000 | 4500 | 26 | 100 | 300 | 14 | LUCAS | 2000/12,0 |
| F | 1000 | 4500 | 26 | 100 | 300 | 14 | LUCAS | 2000/14,0 |
