no it wont. the even fire 3.8 and GM4.3 and 3.8 and dodge 3.9,3.7 and isuzu 3.2,3.5 have a cylinder fireing on each bank at the same time which wouldn't allow any vacuum scavanging.
the H or X does absoutly nothing for an even fire 90 degree v6. Smokey Yunick back in the late 70's and early...