It depends on what parts you want. For a transmission (4 strokes dont have them built in like 2 strokes do) you have a couple options. You can go with the qmatic for about $300, or a box like mine if Jeff will make you one (dont see why not, you just need to ask) for $200 or the AGK box for 200, but Jeff's is better than agk's. I recommend a sprocket adapter, and there are a couple of choices for that as well, pirate cycles, sportsman, and maybe manic mechanic if they are up and running. You'll want some durable tires, good suspension (many choices for that as well, just depends on what you want as far as looks, quality, and brakes and what you want to spend on a fork), good brakes (drum or disc, depends what you want). You will also need to bend your pedal cranks, because even the wide offset pedal cranks may not be wide enough. mine were not. I had to heat and bend them. You will also probably want a cruiser frame, because I doubt a 79cc predator will fit in your mountain bike frame. You'll need heavy duty wheels as well. There are also several options for that, it just depends on what you want and how much you want to spend.