1974 is probably right. The Rod Shop was doing high rpm small block engine development for Chrysler in 1973 and 1974. At the end of that program is when the W2 heads were utilized. The engine used an aluminum tunnel ram with Holley 6109 carburetors. I'm trying to find out what tunnel ram manifold was used at that time. Just trying to find out if it was a Mopar piece, Edelbrock, Weiand or something else. Any help from anyone would be very much appreciated.