Quote:


Good job ignoring the fact that your 76 440 has a whopping 7.5:1 of factory compression ratio. Compression = efficiency and anything out of the late 60's would have had a CR in the 9's most likely. Then you take a smogger 440 and add a bit of cam to it, well you didn't have much cylinder pressure to start with any any cam over a stock passenger car/lo-po cam will drag down mpg.



Not ignoring anything here. I know this thing aint the best factory design (kinda my point), but the OP's car aint pushing much past 9 either. The engine i ran before this one was a 67, with the stock "10:1" and it was a pig too. It wasn't as nice an engine as the current one, but the CR made up for it. Both got about the same mileage in this car. I guess what i'm saying is that the OP has a factory set-up, which is hardly what i'd consider an efficient engine design (sorry Mopar gods...). If you were to go through the trouble to install a 500 Caddy behind the 727 in the same car (uh oh... blasphemy!) just to prove a point, i guarantee you'd see a dramatic improvement in MPG and power... despite the obvious cid increase.

Quote:

The exhaust he has is fine for his app.



I disagree.

Quote:

No way it is causing that low of a MPG.



I agree. I didn't say it was CAUSING the problem. He asked what he could do to improve MPG. Replacing it with an optimized system certainly would.