Yes 6-pack is holding me back. I was thinking this combo would have given me 650 however I wanted to stay with the 6-pack intake. It is an original A-12 set up with aluminum manifold and vacuum pods on the end carbs. The numbers were with 2 inch dyno headers. We lost a little with 1 7/8 headers for a few pulls after that. Can't remember what we had I will have to check the dyno sheets.