i first put on the offenhauser dual manifold and had it for a couple of years and saw an improvement. last year i added fenton headers and saw a distinct improvement in performance. as far as fuel ecomomy i never checked before and have nothing to compare to. but i do like the improvement in performance noticeable enough i am not going to change my 2.73 nova gear ratio. if i want to stop light race i use my PT cruiser turbo, ( will FLY ) just got back from sons in indy had a lot of fun with the PT would like to have driven the truck, 95 degrees no ac in truck, wimpy RON
