jcolman said

My 340 gets about 8-9 miles / gal. so I feel your pain! I also have a street/strip cam, Headers, etc. 727 transmisision. Rear end has 323 gears. I have a Holley Sniper EFI sytem that is pretty well tuned but might be a tad rich.

Part of the reason you are not getting any better gas mileage is the 3 speed transmission. My car turns about 3200 rpm at highway speeds (70 mph). I'm going to swap out to a 5 speed Tremec which will allow crusing at a lower rpm as well as more fun shifting gears.

Nice looking car by the way! I love the look of 18" wheels on these cars. Here's mine.

Thanks for the post. You have a beautiful car. Do you get any tire rub with the 18" wheels? I am getting some in the rear. Not sure if a new pair of shocks is in order or if I need to go with air shocks? In terms of the gas mileage I may just have to put up with bad mileage but I believe I should be getting better than 6.

I have noticed that the car gets into 3rd gear quickly (35 mph) and while I have not noted rpms (it does have a tach) at different speeds it feels like the rpms are higher than you might expect which when I first drove it I felt would limit the top end. Which is fine I don't plan on going 100 mph in it!

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