Hey guys
I have a PD36 on a PD 17X48. I'm in the process of ordering up grades for the motor. I'm ordering a Mikuni carb, Marshmallow X2 Exhaust, Iron Mountain and a 12x14 Hopkins prop. Here is where I do not understand what to do.

One: is the heads worth ordering without changing the pistons, rockers, and rods.

Two: I have been told I should do the same up grade listed above, but I should also add a Cam. I don't know anything about what the Cam does.

Three: is the BPS crossover exhaust better than the MM, or just person preference

Please guys..... Help me make this choice for my motor. I just don't know how much all of this is going to change the motor for Good or bad or what to really expect from the cam.

Thank you very much in advance.
Ryan