Ride height has changed several times over the years, measuring fenders is convenient and can be informative but the factory method is the most precise and eliminates the tire height as a variable. It gets the suspension geometry where the factory engineers wanted it
in front use a - b a bigger # means a lower ride height
The earliest( '69-73) street, front spec for all non turbo/turbo-look cars is 108+/-5mm for all markets, even lower is used for competition down to ~ 135mm
in '74 or '75 US mandated bumper heights changed the US spec to 93+/-5mm(Row remained @ 108)
in '78 US/Canada/Japan spec again changed to 99+/-5mm(Row remained @ 108)
for '84 up the US spec went back to what RoW had been all along 108+/-5mm
in back use B - A here a bigger # is a higher ride height
'69-73 all are 12+/-5mm
in '74 or '75 US mandated bumper heights changed the US spec to 37+/-5mm(Row remained @ 12)
in '78 US/Canada/Japan spec again changed to 37+/-5mm but Row changed to 16+/-5mm
lastly all were unified @ 16+/-5mm for '84 up