REPLACING HEAD GASKET

I am getting ready to replace the head gasket on my 1966 evinrude 18hp. I bought a parts motor today off craigslist and thought I'd take the head off it as practice for my good motor while I'm waiting on my gasket to come in. I noticed that there is alot of carbon build up on top of the pistons and the cylinders are fairley dirty as well. Should I clean this off and if so what should I use to clean it with? I thought about carb cleaner or brake cleaner. Will that hurt anything if I oil the cylinders up when done?
Thanks Eric

You should be OK.Just make sure the piston your cleaning is on the top of its compression stroke & you cover up the other cylinder to make sure no dirt gets in there.

If the motor you are working on is still running you should do a seafoam decarbonising.

+1 on using the Seafoam