L88, you're going to have to find a shorty header. most long tube pipes are going to exit behind the opening for the sidepipes. trust me ,i know for a fact. early 80's had a shorty factory header. not as effecient as the long tube,but less restrictive than the ram horns.
you'll have to block off the emission plumbing but they will work.check with Gary(copdogcorvette) i think he still has a set of the factory headers.
robin