Unfortunately, Tecumsehs are very infamous for that. There are plenty of medium frame 8hp Tec engines on snowblowers. I've obtained several non-working blowers with good engines from Craigslist for $50 or less.
Well looks like the Sears HM-80 may turn out to be a parts engine...... Confirmed my suspicions and it is a tapered shaft. The points are also really crusty. I'd like to find a newer engine with the points-less ignition. Unfortunately I can't even use this block because it doesn't have the mounting points cast into it...
This is an HM80 points motor and it has enough torque to crawl out from under you if your not careful with the throttle. just put the crank from the blown up motor in that sears and run the $h
!t out of it.
The tapered shaft crank engine uses a different side cover than my original HM80 too. The the original one had the 2nd pulley on the cam that I just cut off. So I could do it, but I'd have to use the cam as well.