Here is the final setup, with the piston at TDC, and the pickup directly at the existing timing mark. Not the that the missing tooth is 90 degrees ahead of TDC. This makes the first tooth at 80 degrees BTDC. The MegaSquirt does not particularly care where the first tooth is located, but it does have to know to calculate timing. At this point I had not decided to use the EDIS module or to route the VR signal directly to the MS, so I stuck with standard 4-cylinder EDIS tooth timing.