I also did a groove on this too, there is a 750 elderblock carb on it. I used the medium bit becouse the walls wasn't very thick. Wasn't able to get a fair milage reading before the groove, becouse it's hard to keep your foot off the gas. The vehicle is so much fun to play with. Knowing that the groove works best on carburators. I did it and tryed very hard to stay in control to do a milage check, and got 17.9 mpg. I believe thats is close to double. It was thirsty before.
wow Gene to get nearly 18MPG outta that beast is right respectable! A 340, w/ a cam AND 4.11's, that Duster just wants to scoot! Hard to keep the foot outta that one! If you have the 8 3/4" rear it's fairly easy to swap gears, there's another ratio I think 3.94 ,3.76 and 3.55 too...
but need the whole center section, and of course cam/gears, really everything needs to match up right...
wonder if more MPG is available thru changing rods/jets in the Edelbrock? But would need care to avoid going too lean on such a thrill ride! MPG Remedy...?
I've got a '74 Dart Sport, w/ a 225 Slant six, stock except for Super Six intake/Carter BBD carb & Dutra Duals exhaust. The BBD lacks enough "meat" under the throttle blades to Groove it though. I changed the awful 2.76 gears to 3.23's in the 'lil 7.25" rear end. Not many choices for a carb. swap on this one, a 4 bbl is just too much for a stock Slant.
Edelbrock/Carter AFB is my fav. 4 bbl carb, so forgiving and tuneable, AND Groove-able too!
congrats on great results Gene!
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Gadgetman Reno, NV