It has only been a brief period of time since we added the blue and white '66 Chevrolet C-10 Fleetside to our collection of in-house project trucks. At first glance the stubby little pickup we dubbed "Farm Fresh" seems like it's in pretty rough shape. But beyond its cosmetic appearance, a closer inspection reveals that all the paint on the '66's original body panels is original, and a quick glance at the odometer reads slightly over 80,000 miles.

Based on how mechanically tight the truck performs, coupled with the fact that it still has a pair of original-equipment T-3 headlights in place, it's our guess the indicated mileage is correct. Another good general indication of originality was that the build sheet for "Farm Fresh" was still sandwiched between the seat springs and the foam underneath the seat. For any truck owner, discovering the build sheet still in place is a lucky break, to say the least. The details revealed are so specific that they even include all the information about the dealership that ordered the truck brand-new from the factory. Our '66 was built at the Fremont, California, plant for a dealer in Yucaipa, California, not far from where our friend Steve Bentley found it for sale in Southern California's high desert.

Originally, our '66 was equipped with a 292-inch six hooked to a compound-low four-speed transmission transmitting power into a set of 4.11:1 gears. Somewhere along the line the 292 was uprooted, with a stock two-barrel 327 plucked from a '70 El Camino dropped into its place, but the original tranny, with its "granny gear" and deep rearend gears, was left alone. In the great scheme of things, ordinarily our first steps toward increased performance for any classic truck would be to hop up the engine and worry about the transmission and rearend gears later.

But in a departure from our usual practice, we chose to upgrade the '66's transmission instead. This was mainly because of the high level of discomfort caused by the bone-shattering jolt to the shoulder with every missed shift due to the compound four-speed's naturally sloppy shifter's unwillingness to change gears at a decent clip. After asking our friends over at Super Chevy magazine if they had any good advice on how to improve on the '66's transmission, we contacted the folks at Classic Chevy 5-Speed in Carlsbad, California, and made some inquiries into the availability of a kit to fit a Chevy pickup. As it turned out, Classic Chevy 5-Speed was in the final stages of releasing a complete kit that will work for '67-72 C-10s, as well as '60-66 C-10s such as ours.

Of course, before we made the final decision to install one of Classic Chevy 5-Speed's kits based around the Tremec TKO five- or six-speed overdrive transmission, we did a little research into what the benefits would be. Right off the bat, with first gear at 3.27:1 on a TKO-500 or 2.87:1 for a TKO-600, the Tremec gearbox would launch our truck with a first-gear ratio twice as high as the compound four-speed's first gear, meaning we would actually have a useable first gear.