Re: Which test wheel for '89 XP150?
Look on the specifications pages. These pages should be the first pages of the manual. Along with torque specs, horsepower ratings, etc. Should list the test wheel part numbers for the V6 engines made that year. (my old 78 manual lists 387388 for all V6 models that year.) Once you get the number, you may want to check with a dealer, as it is possible that it may supercede to other numbers that will work equally well. I am sure that this old number or any in this supercession chain will work for you. The point is that if you are shopping on ebay, you want to know all the potential numbers that may work for you.