I've always been a fan of MSD ignitions. I fitted one to BIGRR's RAT205 for example. It runs and idles so sweet. When this unused, brand new MC-1 came up on ebay for $75 I couldn't resist. Luckily nobody else made a bid. The MC-1 was designed for motorcycles, back in the day when they ran points, thus it's actually a two channel MSD. It's perfect for wasted spark applications such as the XU10J4R. I'm not sure what I'll do it with yet, but probably the red 405 daily driver.