63 plymouth 318 Fuel mileage?

[junkyard junky]

Just pulled the 318 out of my 63. Its a 4dr with automatic transmission and was curious if anyone else running the same setup. If so what kind of fuel mileage were you getting? I have a 68 383 engine and trans I was thinking about using. A mopar website said that it should have a 2.76 rear end gear. Thanks.

 

[threewood]

My 62 Belvedere 4 door, 318 2bbl, auto, 2.76 rear end gets about 18 mpg last road trip I took.

 

[62savoyguy2]

Still better than some of the computer controlled junk they call cars today. No one makes a V-8 that gets that mileage, no matter what their mileage charts say. Work for a dealer and see it every day, people that complain their car does not get the mileage the window sticker says. Computers????????.

 

[Darter6]

My 64 Belvedere 318 Weiand intake, 600 AFB, dual exhaust and 2.76 gear.28'' tall rear tire.Easy 18-20 mpg.Now for me most all roads are open highway very straight with small hills no mountains, ruff terrain or snakey switch backs. Where you live will make a difference.

 

[AMX364]

So many things effect gas mileage. I used to get about 2 mpg increase by playing with springs in the distributor and different timing. I have also changed metering rods on the side of the highway and picked up about 4 mpg for the highway, could not leave it at that setting for driving in town, to close to the ragged edge.

Normally the best change that I get on most cars is a good dual plane highrise and 4 barrel carb setup with a hot air tube for winter driving. Headers really help above 3000 rpm, which is not what you should be driving. 95% of your driving should be under 3000 rpm.

For winter driving I used to have a single blade fan which helped increase by 3 mpg. This was not so good sometimes for the summer or if you had and wanted to use AC.

You must keep good records of any changes that you try and what the results are. Gas mileage changes take a lot of time and driving to find what happens. Cruise control costs .5 mpg loss, however it might allow you to able to walk after a long drive.

 

[fwi]

Romeo, Where did you get that beautiful car?

 

[junkyard junky]

Nice car Darter6! Thought about doing a 383 swap but then found out by doing some research that I may have a 2.76 rear end gear. Waiting on pulling the chunk out and checking. I'd like to keep it all original. We have some hills here in Ky. Car won't be driven a whole lot due to me having a couple of other vehicles. Mostly going to car shows via the interstate and parkway.

 

[Moparsmitty]

:icon_thumleft:Sweet Bel Darter.

 

[Darter6]

Stupid,stupid me.I got that car with 12K miles on it and owned it for 9 years.Sold it with 17k on it to a guy that wanted a 4 door for the wife and kids to cruise instead of them crawling into his Road Runner's back seat.I sold my drag race Dart and wanted to race again.Stupid,stupid me...........