Ford Modular Motors 1999 and On
Part Number 8734
The MSD unit pulls spark. The stock limiter pulls fuel.
This is plug and play so you just plug stock coil pack wiring into the MSD connector then the MSD connector into the coil pack.
It takes a little creative wiring, but you can get everything under the coil pack covers.
The stock wiring has a rubber grommet where the wiring comes out of the rear of the covers. You will need to remove the grommet form both sides to accommodate the MSD wiring.
Wiring out of the cover.
Covers On
The stock loom had a rubber connection where the wires split from a single loom to a double loom.
I removed the rubber because I needed a little more length on the passenger side. The wiring is run along the firewall.
I mounted the Box on the passenger side with velcro. I added a little super glue to the velcro for a more permanent attachment. I grounded the unit using the bolt that connects to the strap from the hood blanket.
Manual Tranmission
I used the 12V source option to control the unit. I tied it into the clutch switch (switch that kills the cruise control when the clutch is pedal is pushed in.
There is some wire loom on the black factory wires that I removed then reinstalled.
Tap the (blue and white) MSD wire into the (black) clutch switch wire that is closest to the firewall.
You do not use the solid blue wire on the MSD unit. I just tucked in under the dash after taping off the top. The blue wire is to activate the system via a ground so be sure to tape off the top so it doesn't ground itself on something.
Automatic Tranmissions
If you want to use this in conjunction with a trans brake you connect the (blue and white wire) to the same 12V wire the transbrake is operated from so they work together as a single circuit.
Video of a 3500 RPM test. It holds the RPM's nice and steady, unlike the stock limiter which bounces all over the place.