Calling All Mechanical Geniuses

Even with just headers and tailpipes you have a phenomina called 'reversion' where a high pressure pulse is present in the headers when the exaust valve opens contaminating the incomming charge. The tuned aspect of headers minimizes the effect by scavenging but does not iliminate it.

18" individual upturned pipes through the hood might work but the guy at the inspection station will have a fit8)
andrew