I've got a 283 in my 66.It's really good on gas
What carb manifold and cam are you using?

The two barrel is started with was a joke!
We went to a four jet and stock manifold...got better

Big ramshorns duals and a two-plane w/holley it got good

Tall tires,taller diff ratio...now it's KILLER!!!

Doesn't stop but runs fine!!