Drop Resistor Mod
This mod forces the transmission to shift at FULL Line Pressure at all times the switch is on.
A WOT (Wide Open Throttle) switch is best suited for this purpose because the part throttle shifts are extremely harsh and could damage the transmission.
There is a connector with two wires attached to the resistor. The electrical drawing of the drop resistor looks like this. You must cut one of the wires, doesn't matter which one but cut it at least 2 or 3 inches from the connector so you have room to strip and connect to it.
Strip a small section on either end of the wire you just cut and attach a wire to each end by soldering or use a connector. Run the two wires to a switch. Either a WOT micro switch (preferably) as per the picture or a manual switch.
I have a small L bracket I made that attaches it to the intake manifold bolt closest to the throttle body.
Keep adjusting the switch position until the throttle hits it just before or when it hits the WOT position. It is imperative that this switch be a Normally Closed (NC) switch so the circuit is always made until you hit WOT at which point it opens and effectively disconnects the drop resistor from the circuit.
You can do the same thing by running the two wires to the cabin and hooking to manual switch (5 amp rating or higher) but I much prefer the WOT switch because you never have to worry about turning it on or off. You have enough to think about when racing without another stupid switch to turn on and off.
The micro switch I use is rated at 10 amps and I got it from an appliance shop where it is used in a microwave.
Most switches of this type are Normally Open (NO) and this will NOT work.