I have one of those, may not be HF, but the same saw. I picked it up at an auction for $25 What I did was to install a 2 speed motor with 30:1 gear reduction. It will still cut wood OK , but will run slow enough (60 FPM) to cut tool steel. If needed, adding a second pulley to the wheel shaft would make it 16 speed, and boost the speed for wood cutting.
Had I not had the parts on the shelf to slow it down the way I did, I would have just added a jack shaft to give another stage of reduction for metal cutting. For metal or plastic cutting 60 to 250 FPM is a good range. I like to cut most plastic kind of slow so it cuts without trying to melt.
As said above, use good blades. I have my blades made by a local shop and buy M42 cobalt bi-metal. Not cheap, but they last for ever. In fact, I just broke one on my horizontal band saw after 2 years, it was still cutting fine and made a lot of cuts in many different materials from plastic to tool steel.