There was one surefire way to split a Muncie case wide open. It would last forever if it was run in 2nd. gear on the dirt track. The 1.88:1 2nd. gear ratio against a 4.56:1 rear end gave us just the right final drive to work on a "short" 1/4 mile dirt track, 8.57:1! That allowed the car to coast through the turns at around 3,000 RPM, and accelerate to 6,500 or so at the end of the short straight. A "long" 1/4 mile, measured around the infield instead of the fence, required a rear end swap to a 4.10:1 ratio. That's where a lot of the Eaton 3/4 ton 4.10's went! If the trans was run in 3rd. gear instead of 2nd. with the 4.56 gear for the long track, the case would split wide open. Putting the driving load that close to the center of the case overstressed it!
Jerry
