Trigger Offset with Trigger Wizard

[amrcnv8]

I apologize for the basic nature of these questions. I think I have myself thoroughly confused so I wanted to run some questions by the pros.

I currently have the trigger offset at -10deg, so this would technically be 10 deg ATDC during cranking if I understand things correctly.

My TFI Fox Mustang was set at 10deg BTDC from the factory, so I'd like to set it there for cranking and for a fail safe fall back.

Normally you'd time the car with the timing dial set to 0 and turn the distributor until the timing pointer hovered over 10deg BTDC on the damper to set the factory base timing.

The Trigger Wizard wants you to match the big # with the timing light. With the offset at -10 deg (ATDC) and the timing light dial turned to approx 15deg, I can get the #'s to match at the 0deg (TDC) mark on the damper. Originally my brain told me this was to counter the fact that I was timing it at the 10 deg mark on the damper instead of the 0 mark, but it doesn't seem right to me.

Everything I've read says to set the trigger offset to 10deg (10deg BTDC) for a TFI. What can I expect from making a huge change (20deg advance) to get to 10deg BTDC?

Also, will this change only affect cranking or will it add 20deg of advance to the whole timing table?!? Or will it be dialed back out by rotating the distributor to get the big number to match the timing light?

I'm pretty confused as it seems to run pretty well now. Thanks!

[amrcnv8]

I have been thinking about this more. I think my distributor might be off a tooth compared to stock. Still adjusted to the proper timing of course. That would possibly explain why the trigger offset is so far off from factory.

I am going to rotate the engine to TDC and check the marks on the balancer, since it is an aftermarket unit and has several different timing marks on it. I will check the position of the rotor at that position to make sure it is pointing at cyl 1. I'll then clock the distributor one tooth and readjust the housing to line up with #1 again. I'll set the trigger offset to 10 BTDC and readjust the timing using the Trigger Wizard.