i got a 55 chevy convertible. its got a 68 chevelle 327( nominal horsepower),new holly carb, edelbroc alum. manifold and electronic ignition. 4 spd trans and 3:08 gear. the motor runs ok but needs overhauled. i drive mostly on highways and not into street raceing. i am looking to either rebuild or go to a new or rebuilt engine. i like the idea of keeping the 327. but funds need to be used wisely. i need to make her as efficiant as possible. am looking to put a 5 spd in for lower rpm on highway. is there a mathmaticle formula to use to help me figure this out,ie cam,= cubes= torqe and horsepower at what rpm times wieght. what combination would make the best gas mileage going 70 down the road be? i know there would be variations like top up or down, wind velocity and weight,( luggage, trailers, mother in laws).i want to take it cross country next year and want it to be as efficient as possible. hope ya can help me out. thanx moondogmike
Shouldn’t you be reading “Hot Rod,” or maybe “Super Chevy” magazine(s)? They are all about this sort of thing.
A friend of mine gives me copies of “Hot Rod” now and then, and it’s amazing the fuel mileage some of their highly modified cars can achieve on the highway. I’m sure a 5-speed will help quite a bit.
I suppose it all comes down to money. How much are you willing to spend?
Personally, I find it hard to put the words “55 Chevy” and “efficient” in the same sentence. I suppose it all depends on how you define “efficient.”
Mathematical formula? There are probably hundreds, but you’re still pushing a '55 Chevy through the air at 70 mph. That takes some power, and some gas. There are no miracles.
Good luck. Please send pictures of the car and the trip.
Your ole heap is a very collectible car. Before you make changes to it perhaps you should rethink the project. A '55 Chevy convertible with original parts is very valuable. A poorly done remake or restoration could lose value for the car.
Best option would be to use original parts and restore the car to original condition. I don’t know if a 327 was an option in '55.
You have a potentially very valuable car and if you screw it up the car will lose value.
You might consider installing an up to date fuel injected engine.
If you plan on driving cross country with this vehicle, you’re going to run into gasoline that contains ethanol. And with an older fuel system, the ethanol can damage the fuel system.
A friend of mine is restoring his 53 F100. And he installed an up-to-date fuel injected engine. So instead of keeping the 69 302 engine, he installed a 5.0L Mustang engine so there would be no problems with ethanol gas.