my buddies got a old 1970's suzuki 80, runs like a raped ape for how old it is, and looks pretty good to, if your interested shoot me a pm, he lives in NY not far from the border.
2-1 will VASTLEY IMPROVE the bottom end that you already have. I had a mx port, which is low to mid, and the 2-1 carb helped alot really worth the money, and i had a 2-1 dynoport pipe on there to, which made it have the torque of a 4 stroke
the 87 and the newer hubs are different for the sprockets. the older one had 4 mounting points, to where the newer ones have 5. I have a 42 rear, 14 front, and a chain to fit a stock swinger in fairly good condition for a 87 that ill sell ya for 50 shipped if you'd like? or just the sprockets for 25 shipped?