hen overdrive automatics came on the scene they found their way into a variety of modified vehicles, and for good reason. These transmissions were tough, had a wide gear ratio spread with a low First gear and an overdrive Fourth. In addition there was a lockup torque converter that provided a direct connection from the engine to the rearend. But if there was any shortcoming to the 700-R4 it was the throttle valve (T.V.) cable (sometimes called the kickdown cable).

Ironically, the problem with the 700-R4 T.V. cable was often a result of the induction system being used. The T.V. cable controlled the hydraulic pressure in the transmission and in stock configuration the GM carburetors and fuel injection systems had the correct ratio as the throttle was opened to activate the T.V. cable appropriately. Unfortunately, many aftermarket carburetors and fuel injection systems did not have levers with the proper ratio and the result was low hydraulic pressure at some throttle settings that allowed the clutches to slip, which ultimately led to a complete transmission failure.

ith the rolling chassis for our ’68 C10 project complete, it was time to figure out what engine and transmission we should drop into it. In keeping with our theme of “cool driver on a budget,” we hit up the local junkyard in search of some affordable horsepower. What we found was a 5.3L LS engine in a 140,000-mile GMC Sierra. There’s always a bit of risk involved with buying a used engine like this, but we’ve found these GM Gen III and IV engines to be very durable, even over 100,000 miles. 

LS engines are capable of some amazing things. But as pulled from the junkyard, they sure are ugly. With our “new” engine back at the shop, we got busy pulling off all the crusty old wiring and accessories. Our plan was to do a simple cam swap and rocker trunion upgrade to see how much power we could make without breaking the bank on anything fancy. To help us achieve this goal, we called in some expert help. Zach Woods runs the Speedway Motors Racing Engines shop. He spends his days building 900hp circle track racing engines, so he knows a thing or two about building reliable power.

would safely say that 7 out of 10 people were dumfounded when I told them of my intentions to convert my ’69 Chevy from a factory (SWB) Fleetside to a Stepside—that ratio only increased (or decreased, depending on how you look at it) when people saw that I was not only serious but actually went ahead and did the conversion! OK … it’s my truck (and Old Anvil Speed Shop now has a decent/complete Fleetside box in which to use for their ’67-72 All Access bed floor kits!) and I’m standing behind my so-called aesthetic blasphemy!

All kidding aside, I used to be a devout Fleetside fan—but have always had an attraction to Squarebody ’73-80 Chevy/GMC Stepsides, though I never made the backward transition with my ’75 Cheyenne before (regretfully) selling it. With the ’67-72s, however, it wasn’t until quite recently—more specifically, when featuring James King’s Delmo-built ’71 on the cover of our June ’22 issue—that I became more fascinated with the early Steps. (To be fair, Classic Truck Co.’s Spot Thomas’ ’67 Stepside has also been a major inspiration!)