i need help with fuel economy

[Tyler]

I actually made a fuel injected model that goes a good bit better....something like 21mpg, and ~240hp. That one had some quality sliders boosted a bit, though. Sort of a standard "premium" engine.

[nialloftara]

There's never a replacement for displacement. Here's 15.5 mpg from a '83 pickup using offroad tires, a 4 speed auto, and a 548ci big block. no sliders used. This one has a manual locking live rear axle and extra ground clearance for off roading. This is a attempt at a period correct build, so it has a restrictive, emissions compliant, exhaust with a 3 way cat, low compression hypereutectic pistons and a low end torque oriented cam profile. Even with all that it can still do 0-60 in under 10 seconds, it can run with a '91 chevy c1500 454ss with better tires.