Should have mentioned this at Chicken Central l could have shown you the stuff I've been collecting for an efe engine. For big power you need straight cut gear's for the crank and clutch. You should be alright for 200/220hp though with lower comp.
I bought an early r1 arm for 30 English quids cut the brace off welded it onto the lower side of the 7.5 slabby arm and had it powdered in chrome effect
Your's was one of them @Paulm @Wee Man @Blubber my Turbo Scratcher and the Turbo Harris as well as @fatblokeonbanditteapot which is now owned by me soon to become the sleeper Turbo Pot
I'm having a similar problem with a b12 motor but it's not the electrics or the lump. I have a set of standard b12 carbs from a recent running bike and the lump sprung into life when these were fitted. Other set of carbs have been cleaned and serviced but refuse to play nicely