The 123\JAG-6-R-V-POS replaces most 6 cyl. distributors that were used in 3,4 litre, 3,8 litre and 4,2 litre “XK”-engines.
This unit offers “Positive earth” option. This means the unit can be used on positive earth cars. ( + of the battery connected with the chassis of the car) It is also possible to use this unit on a negative earth car.

The unit offers 16 different advance-curves, that can be selected via a little switch. This is a great feature for easy fine-tuning your engine!

A good book is “How to powertune Jaguar XK-3,4 3,8 & 4,2 litre engines” written by Des Hamill.
( see : www.velocebooks.com )
This book, in combination with the 123\JAG-6-R-V-POS, gives you all the tools necessary to powertune your Jaguar ! The unit offers a maximum total of 16 advance-curves to be selected by the end-user.
Please take a look in the table for available advance curves.

Jaguar – 6 – R – V – POS = Jaguar stands for the 123ignition type 
Jaguar – 6 – R – V – POS = 6 stands for the number of cylinders 
Jaguar – 6 – R – V – POS = R stands for straight distributor cap 
Jaguar – 6 – R – V – POS = V stands for vacuum advance
Jaguar – 6 – R – V – POS = POS stands for positive earth