You almost have to feel sorry for the transmission. In the grand scheme of things, it always ends up playing second fiddle to the engine behind which it resides, and that really isn't fair-especially since the engine would be nothing more than an expensive noisemaker without it. If you want your ride to get down and boogie at the track, choosing the right transmission with the proper internals and torque converter is critical.
Our '70 Fairlane project car came from the factory with a utilitarian 302 small-block and a C4 three-speed automatic. When we first peered under the big Ford, we were struck by how small the C4 trans looked. To us, it seemed far too dainty for a performance transmission. Of course, we were wrong. Turns out the C4 can be built to hold a boatload of torque, and it has the added benefit of being lighter in weight than the portly C6. Given that we'll eventually be running a 408 small-block, sticking with a C4 trans seemed like a smart move: we keep the weight benefit, and installation will be a direct swap.
The big question is how much massaging a C4 requires to hold more than 500 ft-lb of twist. Rather than guess, we called Hughes Performance to find out what would best fit a street-guy budget like ours. We found there are many ways to build a performance C4. Knowledge is power if you want a unit strong enough to fit your application, yet not filled with expensive parts you don't need. We're all familiar with the mechanics of the internal combustion engine, but the functional workings of an automatic transmission fall toward the fuzzy side. To fill our brain with the ins and outs of the C4 tranny, we headed to the Arizona desert for a build session with Hughes Performance.