The red/blue wire runs through the stock neutral safety switch between the ignition switch and the starter solenoid. If the contacts on the NSS aren't closed when the transmission is in neutral (or jumpered together) the solenoid will not be energized. You will need to find the connector that connects the wires to the stock NSS and either connect them to the Tremec NSS or jumper them together. I strongly recommend that you use the NSS on the Tremec. They are there for a reason, and called SAFETY for a reason. I knew a mechanic that had one of his sons helping him, asked the son to crank the engine while he watched from the front of the car, car was in gear, started and pinned the mechanic between the bumper and garage wall, broke both legs and messed up his knees, and he almost lost his business. Not to mention how his son must have felt.
Use the NSS!!!!