actually the output shaft of that size was pretty common on them old briggs from what ive noticedI have never seen an engine with such a short output shaft. At least that's how it
looks in the picture. How long is it, about 1 3/4" ? I guess you could put a centrifugal clutch on it. You would never get a torque converter on it. It is too
short for that. Is it 3/4" in diameter ? Have you been able to get it running yet?