Ok so turns out I talked too soon! It appears that its the ignition module that is putting out a really weak signal inconsistently.
Anyone recommend anything to replace it with? It is a presolite distributor with a pertronix module. Im running a MSD blaster 2 coil with no ballast resistor. 351w PCM LH rotation.
Buying things in the states rather than here seems to be quite economical and you guys have been doing specialised marine stuff better and longer than us.
Any help is appreciated