I have just replaced the complete Lucas competition system on my 1700 Xflow (black box failed and I could not afford the replacement cost) with a Bosch system from a Fiesta/Escort with the 1300cc Valencia engine. This is a direct replacement for the Kent engine.
T he modification has worked tremendously well and I have noticed a significant improvement in the running of the car (and the fuel consumption !)
I obtained 2 distributors (1 for spares) from the scrap yard complete with amplifier packs (part of the distributor) for £5.00 each. I then modified 1 of the distributors to remove the vacuum advance and map the advance curve suit the cam. For mine it was 14 degrees static with the advance starting at 1300 RPM increasing to a maximum advance of 34 degrees at 3700 RPM. The mapping was a bit trial and error and took a couple of hours to do. The initial and maximum advance can be altered by slightly bending the spring posts and bob weight limiters. This is easy to do through a hole in the distributor body conveniently located by Mr. Bosch for this purpose.
The wiring was quite simple with just 3 wires from the amplifier connected to the coil and earth.
black + positive side of the coil
green - negative side of the coil
brown to a good earth
I went for this set-up for several reasons. Firstly it is dead reliable, secondly parts are easy to get, thirdly it's cheap and fourthly the Bosch distributor is far better engineered than the Lucas one. The car I removed the distributors from had done 75K miles and there was no wear in the spindle at all.
The biggest expense was a new distributor cap with side exit leads, this was £10.00.
the part number for the distributor cap is:
Motorcraft - 5005566
Halfords - HD2 515
intermotor - 45800
Hope this helps
Tony