The World's Most Powerful J-Truck?
Fullsize Jeeps are the Rodney Dangerfield of the off-road world; they get no respect. Overshadowed by the "Big Three" fullsize trucks and snubbed by their short-wheelbase brethren, they don't seem to fit in anywhere. But sometimes not fitting in is a good thing. Instead of following trends, Jim Rhodus decided to turn his '77 J10 into a vehicle that would turn heads and demand respect. Jim bought his J-truck when he was only 16, and it was on that old bench seat where he first fell in love with sand drags. The bench seat fell by the wayside a long time ago, as did many of the factory components, but over the past 20 years Jim has transformed his fullsize into a sand drag monster with a niche all its own.
One of the keys to going fast is having a good power-to-weight ratio. The key to a good power-to-weight ratio is more power and less weight. Duh. As the owner of Rhodus Fabrication in Shandon, Ohio, Jim knows a thing or two about how to set up a chassis. To that end, Jim back-halved the J10 in 2000. The frame was replaced with 1 5/8-inch, 0.134-wall tubing that reduces weight and strengthens the chassis. The tubing ties to the internal rollcage and extends all the way into the engine bay for safety and torsional rigidity. Now all of the power is transferred to the ground instead of twisting the frame.
When the rear chassis was built Jim took the opportunity to ditch the 4-inch-lift springs on the truck and redesign the suspension. He had a vision for the entire truck and instead of spending time and money twice, executed it all at once. A custom Rhodus Fabrication rear four-link suspension that uses 1-inch, 0.156-wall DOM links and 3/4 x 5/8-inch FK chromoly rod ends works in conjunction with QA1 coilovers. Up front, more conventional leaf springs are used with QA1 shocks that help transfer the weight to the rear of the vehicle.
Previously the J-truck was powered by a 565 ci big-block making "only" 900 horsepower. Fellow racer and friend Jason Steele offered to build a new engine for the truck with one catch. Building an engine is cool, but knowing that drivers get all the glory, Jason wanted his chance behind the wheel of the J10 too. Once the deal was struck, Jason got to work building a 401 ci V-8, but this is no AMC motor. The small-block Chevy displaces fewer cubes than the previous Rat engine, but it makes up for it with a Procharger F-2 supercharger that pushes 34 pounds of boost through the intake. At the big end of the track, the engine is spinning 8,200 rpm and the belt-driven, centrifugal supercharger is turning a whopping 72,000 rpm. To handle that kind of cylinder pressure, a Dart Rocket block and Dart Pro1 aluminum heads were used in conjunction with a Callies forged steel crankshaft, GRP billet aluminum connecting rods, and JE forged pistons. The engine injests alcohol through a C&S 950cfm blow-through carburetor with electronic float bowls and exhales through custom Rhodus Fabrication headers. Being down 164 cubes to the former Rat, how does the Mighty Mouse measure up? Dyno sheets show a mind-boggling 1,687 horsepower at 8,000 RPM and 1,182 lb-ft of torque at 6,900 rpm.
The quadruple-digit power is routed through a Powerglide two-speed automatic. The 'glide is the transmission of choice for drag racing, as they are light and don't take a lot of horsepower to turn. The transmission uses a Dedenbear case, a Cone 1.69 straight-cut gearset and valvebody, and a super-loose PTC 6,400-stall torque converter. A short driveshaft connects the tranny to a divorce-mounted NP205 transfer case that uses a Ford input shaft with a Chevy case for the passenger-side drop. Driveshaft hoops keep the driveshafts in check for the front and rear axles.