chevyvan77,
I live in the country so 75% of my driving is on gravel, usually around 40-45mph.
I do have a 4 barrel carb.
Overdrive would help but...oh well.
My rear end ratio is 4:11.
So going down the hwy @ 65-70mph is about 3,000rpm.
I've had tune-ups and really it runs quite well. When I first got it I drove it home on interstate and got 14mpg and was totally impressed.
I do agree though...why buy something new if the gas mileage is the same? As long as you've got a vehicle you enjoy I guess that's the most important part.