I can not seem to figure out what causes the erratic timing on this. Still working on fuel its not that close yet, but the spark problem bothers me because it will come and go and change commanded spark by as much as 5 deg. The problem seem to show up when I went to Speed Density with the Patch. But it wont do it every pull. The 688 hp log and tune show solid timing, the "timing" log and pull show erratic timing pull and it does not seem to be IAT or ECT related.
688hp.hpl
688hp.hpt
timing.hpl
timing.hpt