Cylinder Head question for 1964 slant 6

Hi again, looks like we have a 75 head on it now. My husband would really like to get it back to original, (the motor is original). I found a couple of 2206035' which is what I need but one has a -5 after the casting number the other a -A,,,,,,, What does that mean? Thanks.... Can't wait to get it finished and post some pics!!

at least get a 169 casting head on it... the 169 has some updates vs. the 035 but if you have to have it perfect get the correct one, externally they are identical other than the temp sender...