Originally posted by bmweuro,
Half of this thread has nothing to do with helping this person out. Crazy! Find a used rear drive and start there. That will be your best investment for getting a little more low end and more usable power in the right RPM ranges. I have done this on a few different rigs and it always helps. I am speaking from almost a quarter of a million miles on Airhead sidecar experience.
bmweuro sounds like a man that knows. I agree with him 100%. No need to over think this. Many people have done exactly that in the past, and there is no need to reinvent the wheel for what the original request was all about.