Riddle me this...

I need to work on the carburetor. I know I've got a blown power valve. Let me get things sorted with that and then I'll see what's up. This was supposed be an easy gear ratio question...lol.
Yeah it's funny howchit goes.....
How do you know the PV is blown?
If you swap it out, put a 10.5 in there. 6.5s are for racecars