Sorry for beating a dead horse about tire size

Here's one chart I've run across. Picture are not perfect but you should be able to figure out which one you have.
View attachment 1715434098
Now we are cooking with grease. Visual aid, I like it. I have a 7 1/4 so sounds like the 275 on a 8’’ wheel with 4 1/4 BS will work. Right? If so back to 2 of the original questions. The spacer? Do I need to do that and how much room will I have from the top of the tire to the top of the wheel well? Thanks 66fyssh! Appreciate the info, I’ll hang on to that.