Well, I guess it's like when folks switch the engine displacement number on the fronts of the old Chevy muscle cars. Except they usually get bigger numbers than they should.
One day at my mechanic's lot, there was a Nova that looked pretty much stock, but had (don't quote me, I'm not good at remembering cu.in.) a 454 with a blower, but the little badge was for a 289. I love sleeepers.

:flash: