Your guzzi not running smooth? Probably this is the problem? Ignition leads, sparks starts flying all over it. It is result of design, hot engine and aging. New ignition lead cost 90 eur and it is pain in the ass to get it from dealer.
I used NGK spark plug caps and beru silicone cable. It is also pain to get.
NGK caps used were sb05e. They fit and have required resistance.
Cable used is Beru, you can also use any other cable. I used silicone, because it is better heat resistant.
You need to remove old terminals from ignition coil, also used are protection covers from stock cable.
I also used some zip ties and heat shrink. I wanted cable as good as possible.
Everything fits nicely and stock spark plug cover fits on as on stock cable. Bike now runs great!