So I picked up a 1989 420 on Saturday. It needs paint and a tuneup, but for the most part it is in decent shape. The engine surges at full throttle, but runs smoothly at lower rpms, so I would think that maybe it's starved for fuel at the top end or needs the carb cleaned. I plan to buy a 3pt and load lifter for it and use it to move stuff around the yard and what not until I can find some attachments for it. Definitely a lot bigger than my 210 and 185.