That is one clean setup, I wonder how it sounds through those big pipes. I've personally seen 5 Pete conventionals with factory 12V71's, Driven a '67 Pete COE with a 12 for while... It was a total beast pulling 125K.
There used to be a hayhauler on I-90 with a red Frieghtshaker truck and trailer setup with a 12 and weedburner exhaust, I think he had a 26' deck before the state changed the length laws. Oh... there was a guy in Quincy that had a Green FL with a 12 too.