While I have my engine out im going to repaint it with a engine paint kit from POR-15. My question is, that im going to paint it black but the block is yellow right now, so how should I go about prepping it? Or should i just lightly try to sand the paint a lil and paint over that? The engine is together so I dont want to be spraying a bunch of paint stripper on it because i dont want to get the engine wet with water.

Wire wheel.

Wash any grease off it with a good degreaser or brake clean.

Then wire wheel/cup on a die grinder or drill, blow loose paint and dust off with air hose.

Just make sure what you paint on the paint's on there solid. You might wan to check in a small hidden space if the two paints work well with each other(don't crack, lift, bubble).

i found out carb cleaner will literally EAT the paint right off(oops).. and all you have to do is use a scrubber brush and it comes right off... then use brake kleen to clean the residue off...