Looks fat. Is this after extended idle or being driven? Carb? Do the mixture screws respond? 7 might be a touch cold. Back it up to a 5 and see what it does.

I ran cold plugs for a long time in the race motor because that's what you're supposed to do. Wasn't happy with it. First pass was a throw away to get the plugs clean. Started experimenting and ended up with stock heat range plugs in it. Engine was happy.