Tyres.... sorry Tires question

You are going to be limited by your wheel width.

If they are 4.5 wide you might be at the limit at 205

If they are 5.5 then 215 or there abouts

Every tire manufacturer shows the min and max rim width per tire size.

My 67 rims are 5.5 wide and my 215s look ballooned on the rims.