I can't be the only one who's had trouble hooking up a speedometer to a modern transmission—especially when a cable can't be used and an ECU converter or pulse signal adaptor or generator is required. While Classic Instrumentsh installation manual shows you how to wire their electronic instruments to both a generator and adaptor (allowing the signal generator to be used with a Ford or Tremec transmission with a cable speedometer drive), there's now a much simpler way. Not only is this method simpler to install, but it makes calibration so much easier than before, too.
Classic Instruments calls their answer to this problem SkyDrive, an electronic speedometer sending unit that uses GPS satellite signals. It updates 10 times per second and with the push of a button it's ready to use. The "little black box" is mounted inside the car, ideally with an uninterrupted view of the sky, to guarantee a good satellite signal. A status LED will light up red when the SkyDrive is powered but has not acquired a satellite signal, and green when it has. Supplied with its own wiring harness, it should be connected to a constant 12V power source (if connected to a switched power source it'll require 1-4 minutes for initial signal acquisition every time the power is switched on), grounded to the chassis, and the signal wire connected to the speedometer. There are also wires enabling a load, such as a warning light, to be powered up at a user-determined speed, and another 12V output wire that stays live for 5 minutes after the vehicle is stationary.
With a T5 five-speed in my lakes racer Model A roadster pickup, the SkyDrive unit seemed the ideal solution to the problem of hooking up the speedometer. But what speedometer? While it's unlikely the car will ever hit 200 mph with the engine combo it currently runs, almost all aftermarket speedometers top out at 140 mph, and the car's already been faster than that. Once again, Classic Instruments had the answer, with their Bomber Series gauges, which not only seem apt for use in such a car, given so many aviation parts found their way into and onto lakes racers and hot rods after World War II, but also because the Bomber Series speedometer runs up to 200 mph. This gauge series was designed by Steve Moal, with a 3 3/8-inch speedo and tach, and 2 1/8-inch oil, fuel, volts, and temp gauges. Sets with or without the tach can be purchased, as well as with or without the bezel assemblies. The latter are what sets the series apart, in my opinion though.
With this particular car having minimal electrical systems, it really only needs a minimal fuse/relay panel. Ron Francis Wiring supplied one of their ideally suited Bare Bonz systems. The panel itself measures 7 1/2 x 3 1/8 x 2 7/8 inches, and is available as a standalone panel or as part of a complete wiring system with enough wire and connectors to take care of basic engine, dash and lighting, gauges, and some accessories, yet built well enough to be compatible with electronic fuel injection. They can be set up for Mopar, Ford, or one-wire alternators, and can be ordered to fit GM, Ford, or Mopar steering column electrical connectors. Or in my case, none! The system you receive is customized to your application. If you're building a basic hot rod with no electric windows, or power seats, antenna, A/C, and the like, the Bare Bonz panel is perfect.
In a further nod to aviation, as well as British sports cars (I am English after all!), I wanted to use a wrinkle paint finish on the dash. The Eastwood Company offers just such a product in aerosol form, which seemed perfect. If you plan on doing similar, pay attention! On the can it says to apply two heavy coats, with no primer, at between 70 and 90 degrees F. This I did and after the paint cured there were some smooth glossy patches, though there had been no further change in the surface finish after the first couple of hours. Seems I didn't apply enough of the coating to allow sufficient thickness for the wrinkling to develop in some areas, so I media blasted the paint off and tried again, with three heavy coats. Though I didn't let it cure for the recommended 12 hours, judging by the previous finish, which was repeated on the second attempt, I hit the panel with a further three heavy coats after two hours. This was probably excessive, as I now have an extremely wrinkle-finish dash, though it is a uniform finish, which I like a lot.