Well, I'm tossing around a few ideas for next summer/fall should my truck not be gone and I & my wife are still employed.
Anyways, all things considered I am looking to build a cruiser with more seating capacity and a trunk to take on cruises and road trips.

My thinking has me looking for a 68-70 2dr B-Body with a 318 (340 spec camshaft)and 4bbl with headers. The car would have an automatic and 2.76 gears. I am wondering what type of gas mileage numbers I would expect to see from that setup.

My other thoughts are I have a truck 360 Magnum with a 600 Holley 4bbl stock cam and a 727 with a 2500 stall. I was wondering if I were to slip that engine in say a 70-71 Plymouth Fury 2dr or 69-71 Dodge Monaco/Polara and throw in 2.76 gears what type of mileage numbers can I expect and what would it run in the 1/4 mile on a good tune? I would think at least 14.9 ET.

Also, what type of mileage does a 70 Plymouth Fury 2dr with say a 383 4bbl and 3.23 gears get?

Lastly, I am considering a 71 Polara 2dr fully loaded with a 440/727 and 2.76 geared 8 3/4 for sale and was wondering what type of mileage I should expect number wise?

Sorry for all the questions, but I am throwing around a lot of ideas to replace one of my vehicles and wanted to hear from those who have real experience. Thank you.

Depends a lot on where you drive - surface street stop & go, or highway.
Accelerating kills mileage as the weight of the car increases. On the highway, tall gearing & better aerodynamics help mileage.
Depending on how many people and how large they are, I'd be thinking A-body if it's large enough for your needs. Low 20s should be pretty easy with the right setup. I think the best I ever saw out of my Dad's 383 C-body was 17MPG highway.

my 71 scamp with just a cam and a 4 bbl on a 318 got 24 mpg w/ 2.76 gear. then i did a lot more and 3.91's and now im down to 11..

Thanks again guys so that kills my theory of building a 20-21 mpg highway C-Body. So looks like I'm back to looking at 68-70 B-Body 2 door cars with small block/auto setup and 2.76 gears. Boy finding one that's not a clone/bondoed/overpriced is going to be tough unless one deal comes through for me. An A-Body will be too small for me. Thanks to both of you though for your responses.

Really an a-body isn't terrible much smaller than a b-body just a little narrower, but whatever, that's up to you. There are some good deals out there for the 73-74 and 65-67 dodge/plymouth b-bodies if you want a full-size car.

Multiply the miles you expect to drive by the different mileages. Figure your costs per year.
Say 22 MPG will cost you 1000, but 18 MPG will cost you 1300 (purely pulled from thin air). Figure that maintenance, insurance, and registration are equal.
Take that figure and compare the cars. I bet you can buy a nice C body for less than the difference a nice B body would cost.