The Mallory is a breakerless distributor that replaces the original Bosch but still relies on old school mechanical advance mechanisms. The 123 is, allegedly, a breakerless distributor that offers 2 programmable advance curves and a number of other features, without mechanical advance mechanisms.

Or so says their site. I've still never heard from anyone who's used the programmable 123, and my own experience with their older models (echoed by others) was frustrating; with results that didn't justify the expense. I've used the Mallory and found that it didn't do anything that a decent Bosch distributor couldn't also do once fitted with a Crane (or similar) breakerless triggering mechanism.

I've sent inquiries that remain unanswered and am now pursuing alternatives. If you go with either the Mallory or the 123, I'm sure there are many other Brickboarders who'll be interested in your results.

Best,

Cameron
Rose City