hey all, i got a stock 460 in a 1984 f-250 with a 4speed manual, it has manifolds and some choked up exhaust and gets about 5-7 mpg, my question is if i were to get a completly new exhaust system installed on it with headers and dual 2.5" exhaust, how much would it improve on performance and gas mileage?

it turns about 3.5k on the freeway doing 70mph and i don't romp on it in the city and still get terrible fuel economy, any help would be appreciated....

Thanks,
~BLaCkSiLo

 

The exhaust will help, but it sounds like the gearing in the differential is your biggest problem with fuel mileage. My advise, spend the money on fuel, rather than a pricey gear change.

Nathan

 

yeah, thanks nathan, that's what i have been doin...

 

A good muffler will increse your fuel economy flowmaster or gibson and a K&N airfilter will give you more horsepower and torq while giving you an increse in fuel economy. good luck

 

thanks...i'lll try thay along with getting a new geared diff like a 3.73 or 4.10 and some 35 or 36" tires