7" Degree Wheel at Front Damper

Unless you're just stupid, you can do the same accurate job with either size wheel. The bigger wheels are simply easier to see.

The bigger wheels are more accurate to read. Since you saying I am stupid.

Its a stupid person that would disagree. Or someone who bought one or is making them. Sure they are the same degree . Think about what you are saying. And your calling me stupid. LOL.

1/2 degree off on the small wheel your almost touching the next degree. You could add 1/2 degree marks on the larger wheel and still see space. If your confident in the smaller wheel use it. You might want to just use a timing degree tape. Its the same thing just much cheaper.

We'll keep our 18" we have been using. Easier to line up and we can see it without our readers.

A quick search shows stupidity

Moroso 62191 Moroso Pro Degree Wheels | Summit Racing

Why is a larger cam degree wheel better?

When it comes to overall diameter of the degree wheel, you’ll find the least costly ones typically measure about 11 inches. As the wheel size increases, the cost goes up. But there’s a pretty big advantage to a larger wheel — they’re easier to read and as a result, can be more accurate than smaller ones. If you check out the accompanying photos, I’ve placed an 11-inch diameter Moroso degree wheel alongside a 14-inch diameter B&B Performance (Stef’s) degree wheel. You can see that the difference on the scale is considerable.
Degree-Wheel-6-1024x683.jpg

The one you have is only about a 7 inch. Ours is an 18 inch.