I have a 67 Firebird with a 73 400ci engine, slight cam, Performer intake, HEI, and quadrajet 4MC carb. I want to add the Ram Air I kit and was told it would mess up performance instead of help it. From reading some posts it looks like the Ram Air kit is simply adding cold air to the carb and not really changing the air / fuel mixture. I am thinking the guy that told me it wouldn't work really didn't know but I may be wrong. Anyone done one of these or knows for sure.