Curious, why would you want to pick a mod2 cam? I know a few places push them on customers and kids buy them thinking they are great. There are better cams for $50 than the mod2... CL, CL 220, CS, CM to just name a few. (sorry I don't have exact prices for them). A Black Mamba Jr is supposed to be a great cam too.
Use the search feature and read about the mod2, it isn't as great as people think it is...
You also have to know what rpm you WILL be running at. Not what peak rpm 'sounds' good to you. When someone says a peak rpm of 9000,
that may sound good to you but will your engine Actually turn that? I doubt it. Maybe a free rev with the wheel in the air but not with you on it and the wind resistance at speed.
You need to be practical when picking a cam. If you are looking for fast wheelie popping acceleration and low end grunt. Stay away from the high rpm cams. Those cams don't have low end grunt to get you going. Ever watch videos of 70-80 mph drag race mini bikes? They are using their feet to get them going because the huge cams don't have low end power or tq.
Are you going to be riding this around your house, up hills, playing around in fields etc? If so you need a cam with more low end grunt.
Please read up on cams before you just go buy a mod2 because you heard of it or because your friends "says" it is the best.
A lot has been written on cams. To many people go out and buy something they "think" or "heard" is best. Sure, the engine will run. You might think it is fast too, but, it would run better if the correct cam is used for your actual riding conditions and type of riding you do, set up, clutch or torque converter, gearing, tire size etc...
Also, if you are using a pull starter, make sure the cam you get has a compression release. Otherwise you will not be able to pull start it easily.
Just my opinions, other Will vary.
Danford1
PS Here is just ONE discussion on the mod2 cam. Keep in mind what is said about the mod2 being a go-kart cam
https://www.oldminibikes.com/forum/mini-bike-discussion/151514-mod-2-cam.html?highlight=mod2