I couldn't narrow down a search to find anything specific on this:

Would there be any value in putting a larger speaker on a low wattage amp? Like stuffing a 10 or 12 inch in there.

I have a Fender VibroChamp XD.
http://www.long-mcquade.com/?page=products&ProductsID=664

Output is 5 watts into 4 ohms.
Speaker is One 8", 4Ω Fender® S Special D Design. I could not find the wattage on this speaker.

It's got external speaker jack so I could find out without hacking the cabinet at least. One thing to take into consideration is that I rarely play this above 3 anyway.

I have no problem with this sound (I love this amp), but these questions must be asked!

Thanks for any input!