First off being a old school V8 kinda guy with a GP I’ll admit no matter what you do to the exhaust, it will never sound better than what it is. I even have to tell the GP guys that I chat with…it will sound like a V^, beacuse thats what it is. On the other hand, the people that have “turbocharged” the 3800 have a ~slightly~ better exh. pretty much sounding just like a GN.= (which isnt much better)
Second, the 3400 is a 60degree engine and I will also admit (I had a 3100…pretty much the same as a 3400 just differnt bore I think) that it does sound better than a 3800. Even though I like the kinda lopey idle my car has.
Thrid, for the sound of the GP in that video…the owner is on the national GP board and he said he had a fender well intake (open cone) which acounts for ALOT of the loud S/C. ALSO, in 2004 they put a revised Eaton M90 on the GP and it in itself is louder that the previous Gen. M90s. I think he may have had a slightly smaller (3.4") pulley as well.