Keyword "suitable" and
the "those" being 16 x 8s,
so like; 245s or more depending on the aspect ratio.
How tall a tire does Kramer want to put on his car?
A 245/60-16 is already nearly 28" tall
A 245/55-16 might be 26.6
A 245/50-16 might be 25.6
A 245/45-16 might be 24.7
A wider profile will be taller.
A more narrow one is shorter.
But I wouldn't put anything more narrow than a 245 on an 8" rim, unless it is a significantly taller aspect ratio. Say a 235/70-16 @~29" tall
But a 255 might pull the inner edges up off the pavement and require too low a pressure to wear properly, so it too would have to be taller. Say a 255/60-16 @ 28"
So that pretty much points to a tire in the range of 27 to 29 inches.
OK then (28 less 16)/2 = 6" sidewalls.
On a 15 x7" wheel
you can run a 215/75-15 @ 27.7" tall with sidewalls 6.3" tall , up to say
a 235/70-15@28 tall with 6.5" sidewalls
But you know, if you really really like the 16" wheels, I guess anything goes.
I remember seeing an 88 or 89 Diplomat with 18" Dodge Charger Police wheels on it! Car was for sale and I don't know what size tires it had but it looked good! Don't know how he fit them and wondered if they rubbed.