Moodog,

 

Glad to here you've got it figured out.  Too bad for that mechanical tachometer.  I mean, having all that weight and drag.  More opportunities for speed improvements there.  When you get the serious ignition systems to really go fast it'll have a digital output.  You can toss that mechanical cable.  Be sure to put a cap over the original feed.  Also, those cap threads are unique.  You can get the perfectly threaded cap from George Orndorf.  Looking forward to Suffolk.  I'm gonna bring my 7 year old son to further help balance the playing field (or perhaps it's a CG issue....Hmm).

 

Larry