I have a 5.3 with a th400 manual valve body. I have the VSS hooked up and the computer shows the correct mph when moving. The computer although doesn?t know if I?m in park or gear. My question is what spark table is it going off of before switching to the main spark table once I start moving? Is the computer only looking at the park table and then switching to main table once I start moving? How do the spark tables work in my situation?