I figured out how to make a external ESC work with a 7427. I tried wiring it into B7 like I've seen in the conversion write ups but that didn't work, it would register knock counts like crazy. I got to thinking and figured the ESC mounted on the memcal and external ESC probably worked the same. So I cut the memcal ESC off, put a 4k ohm resistor between cal 29 and 31 to keep from throwing code 43 and soldered a wire with a spade terminal on one end to cal 32(esc output) of the memcal. Plugged the black wire that originally hooked to b7(esc output/knock sensor) on my 8063 onto my little pigtail coming off the memcal and bingo it works! I've started to get more aggressive with my spark advance as the stock table for a 305tbi is pretty weak. So far I'm at a max of 20 BTDC at wot with the main table plus 3.2 of PE spark and it has really woke up the engine. No knock counts to speak of other than a single one here and there which I assume is not actual knock because in 15 minutes of fairly hard driving with some wot mixed in I only got 5 total knock counts. To pretty it up some I'm gonna cut a slot in the metal PROM cover and put a grommet on it so I can still get easy access to the PROM.