Another thing to consider is a quadrajet. Guy did this on a 292 and from what he said on the free way he saw 20 miles to the gallon...and that's high for a 292 stock as far as I know...quadrajet, clifford intake, headers, hei. You might consider...inline 6's don't produce alot of vacuum..so the small primaries make for better combustion...and when you want to stomp on it...you have huge secondaries. Something to consider. TJ