With this mod you can edit max health and armor and it won't change during gameplay unless you change it through editing the config file.
How to install: install CLEO and CLEO+ and put the "CLEO" folder in your GTA folder
NOTE: to edit max health/armor you need to go in the "CLEO" folder and open a file called "Health-Armor Limit.ini" from there you can edit whatever you want.
NOTE: when you edit max armor the bar won't change in size unlike the health bar but it will still change the max armor limit you would notice that when taking damage.