360/300 magnum Questions/suggestions

I am looking at a car that has the 360/300hp motor.

First question, where would i find that info on the block to make sure its not some other small block

Second question, can i get the motor to produce 380hp by simply changing out the cam/lifters/springs?

Can't afford a new set of heads at the moment so anything i can do to up the hp without breaking the piggy bank would be great