We first met up with Classic Instruments at a trade show two years ago. John McLeod, Classic's owner, and Zac Compton, one of Classic's sales associates, picked our brains about Mustang gauges. It seemed that the guys in engineering were on the fence about their next project. Should they do a gauge cluster for the early Camaro or for the popular '67-'68 Mustang market? The '67-'68 market is undeniably hot, and while there's already a couple of different gauge solutions on the market, there's nothing like competition to improve a product line.
After discussing the market and talking them into putting the Camaro kit on the back burner (sorry, Chevy guys), we worked with the crew from Classic Instruments, including many e-mails and phone calls with Dave Falther, Classic's production manager, to work out their gauge program.
The Classic Instruments gauge set features all electric gauges and includes the oil-pressure and water-temp senders, as well as the correct speed sensor. The fuel gauge is calibrated to use the stock Mustang fuel-level sender, so there's no need to mess with your fuel tank. | 
We begin our installation with the conversion to the Classic Instruments spec pressure and temperature senders. Disconnect the battery, make sure the engine is cold, and then remove the water temperature sender from the intake manifold. You don't need to bother with draining the coolant (just a little comes out because the sender is the high point of the cooling system), but if you have a detailed engine, consider a partial draining of the system. | 
The new sender provided in the kit is threaded into the manifold in place of the original unit. While we've heard of people installing pipe fittings dry, we prefer a little thread sealant on the threads. Thread tape is OK (and all we had available during this install), but a liquid thread sealant is better. |
Providing Classic Instruments with some points of contact for a dash bezel, and following up with measurements and wiring diagrams, as well as Classic's tooling time for mounting the gauges, took the better part of a year. At the end of all this hard work, Classic Instruments sent us a prototype, which you'll see in the photos, so we could test fit it and offer feedback.
Now Classic Instruments has a completed product that we think will be a hit. The new '67-'68 cluster is competitively priced, installs easily, and works like it should. The gauge cluster is available in three styles: the Hot Rod Series with a black face, white lettering, and an orange pointer; the White Hot Series with a white face, black lettering, and an orange pointer; and the G/Stock Series with a black face, mint-green lettering, and an orange pointer. We chose the G/Stock Series for our installation.
Once the sender has been started, tighten it with a deep socket of the appropriate size. As you can see, we had to temporarily remove the distributor to get enough socket clearance (and for a better photo) due to the location of the sender in this aftermarket manifold. Most OE senders are on the driver side of the manifold, so this step will not be necessary. | 
The stock wiring is retained for all gauge senders, so there's no need to add additional wiring underhood for the water-temp and oil-pressure senders. If you don't already have a tach feed wire inside the car, you'll need to run a wire from the coil negative terminal to the dash for the Classic Instruments tachometer. | 
The oil-pressure sender installs directly in place of the original sender on this '68 Mustang. If your Mustang has a small "idiot light" sender for some reason, you'll have to use the included brass fittings to space the sender out and away from the block, like the OE piece shown here. Assemble the provided brass adapters in the kit, and thread it into the engine block to attach the sender in a position similar to the one shown here, clearing the exhaust and power steering (if equipped). |
Our photos are of a preproduction unit, so there are some minor changes to the pieces on the market now. We note those changes in the captions for you.