John, a "318" is an 8V-71. I believe most of the 6-71's got called "238", the most common HP rating. Either one can be made to perform- - - -just ignore the factory-specified top governed RPM by about 200, and then threaten to do a little surgery on your driver with a dull box cutter so he can hit the high notes in the church choir if he actually uses it. That keeps the injector rack fully extended all the way to the factory shift point RPM.
Jerry
