I fitted one but found the trigger ring fitted to the dizzy camshaft (points cam) was floppy on it. To get the best alignment at spark time between the rotor and cap lugs I had to advance to the trigger ring as opposed to the perhaps more preferable retarded (and therefore unlikely to move) position. I used a general silicone and set the ring where I wanted it. Have raced a season with it and she starts well, is smooth and timing doesn't seem to have moved. One thing though, over the years I've noticed cars don't seem to go quite as 'hard' when fitting these kind of systems on a worn dizzy. I put this down to the natural advance that you get at higher revs from the dizzy shaft run eccentricly ( a dwell meter confirms this). I'd say a good dyno'd dizzy tune would regain all this and more though once the basic installation is settled Dan
