These are the plugs I have:

champion RC9YC: I think heat range is 5??? for 10,5:1 with alum heads
Champion RN12YC: Heat range 4??? for under 9:1 with alum heads???
Champion C61YC: heat Range 9??? for 12:1 with alum heads
NGK 7173: heat range 8??? for 11:1 with alum heads???

Are my above statemets true?

Should I try the RC9YC first and go from there?