Sapper,
This was done so they could use the Briggs motors or the PT's on the same base without the use of a spacer ring, which they had used forever on the 18 inch bases with a 4 stroke fitted. Swapping the cranks over is a possibility but something I have not tried. I have so many standard crank motors I will probably never use them all. And then I have about 40 sitting there that I believe have been straight fueled and I haven't looked to see if any could get away with a hone and a new set of rings. Probably never get around to that either
