Something different Building for MPG.

FISHBREATH said
My second project (or co-project) will be to set up my '67 C-barge New Yorker for interstate highway travel. This will start after I begin work on the '68 'Cuda. I want the C-barge to cruise at 80 m.p.h. while still in high torque range, which I hope to be starting at about 2,000 r.p.m. I am not too concerned about horsepower.

It has the original 440, which I plan to freshen and increase power and combustion efficiency. I plan to use 323 gears and keep it automatic. Three speed auto kinda limits my gearing, but the torquey 440 should be adequate for accelerating the barge from a stop.

I will likely use a cam with the same or similar profile as a HP '68 440. I might use aluminum heads from 440 Source. I will definitely use headers.

If I can get that thing to suck 22-25 m.p.g. at 80 m.p.h., I will be happy. Of course, I would expect to get more m.p.g. at 70 m.p.h.

What do you guys think?

I think it would be hard to reach that level with a 440 just because you have more bore than you really need just to move you around (also remember that huge C-body weighs less than most new cars of smaller size that are often powered by V-6's). With 3.23 gears you definitely would be cruising at higher than 2000 RPM, probably closer to 3200 RPM at 80 mph (which is why you really need OD no matter what, even with 2.76 gears). I'd recommend closed-chamber iron heads because you'd have less wasted energy being absorbed into the heads instead of pushing down the piston, and you'd have more compression with more detonation resistance (if you use the right pistons). I think a modern fast-ramp cam would be better than the old HP 440 grind also because you'd get more torque across the entire RPM range.