Where would i find the stamp teling me what motor i have...ex. b16 b18?

 

If you are looking straight down at the valve cover, look slightly further down, and you will see your header/exhaust manifold coming out of the head, look to the left of that, and a little below where the head meets the block, you should see a flat part of the block with some stamping on it, that is your block code. It should say B16A2 or B18C1 or some 5 digit code if it's a USDM motor.

It is directly under the word "THIS" :

 

thanks