With the Holley system up and running, select the TCC lockup screen under the Basic I/O tab on your left. In the pic below, you can see it does not allow speed to be used as a parameter for lockup like the stock computer or Code 59.

To set up the system to receive a digital speed signal from the DRAC, use one of the inputs on the Holley. Tie into the light blue/black wire coming out of the DRAC with a simple wire splice connector. This wire goes to the speedometer. It is wire 824 in this picture.

Here is a blurry pic (sorry!) of the splice at the DRAC.

Next, configure the input settings on the Holley to read digital speed.

Here is a shot of the "CONFIGURE" settings that I used. I can't tell you why they worked, but after much trial and error, these settings give a speed that is read by the Holley that is very close to the speed on the speedometer. Your setting may have to be adjusted slightly based on tire size, but this should be close.

Now goto the Pin Mapping in the Holley to accept the input at the proper channel and type of signal.

Now on to the output. The TCC is engaged by a negative trigger. This is how jumping the ALDL with the upper left and upper right pins on the ALDL will force the TCC to lock up. I did another splice into the upper left wire going to the ALDL. This is the pin that controls TCC lockup when grounded.

Next, I configured an output channel that would provide a negative trigger when certain parameters are met (i.e., when I wanted the TCC to lock)

Then configured the Pin Mapping to have the proper output signal (ground or G)

Here is a shot of the "CONFIGURE" screen in the "OUTPUTS" area of the Holley program. These are the conditions I set for lockup, and it works great. It is also very easy to change them. I did not use any relays of any sort, as after conversations with others smarter than me, it was determined that the Holley is capable of directly grounding the TCC with out risk of harming the Holley.