If you have the Lucas 14 CUX Hotwire system, then you don’t fit a ballast resistor. The coil that best fits the Plus 8 is this one https://www.ebay.co.uk/itm/154433137459?epid=1229815149&hash=item23f4eeab33:g:0I4AAOSw9iNfcyEz.
Agreed , but that is the standard 14CUX system , and OP has a Mallory Unalite distributor fitted , which does apparently require a ballast resistor.
This distributor was very well thought of in its day , and definitely not cheap, so I think it would be worthwhile persevering with it. It will however fetch a pretty good price on the second hand market, more than enough to buy the components to take the system back to standard IF that was the chosen route.
I used to use an RPI ignition amplifier, but had nothing but trouble, so I reverted to standard which cured that one.
