I will swear on a stack of Bibles (or Korans!) that mine gets that mileage while going 90 - 100 MPH for an hour in 6th across Nevada. Yes, I've done it AND checked the mileage carefully. I AM a converted "grandpa" who used to get 10 MPG with my modded 454 (461) in a 2nd gen!

Buy the BBC for torque appeal, buy the LS for long haul work.

Edit: And by the way, when you read US mag reports, you need to add 20% to mileage figures ... their gallons are that much smaller

 

BTW I would go witht he LS1. I like the old iron too....thats basically all ive driven for 15 years. I was going to start rebuilding my 79Z and leave the SS alone. Nope, its going to have to wait.....the LS1 will be modded first. The whole package is awesome...accleration, handling, top speed and good fuel economy to boot.

I should also add, my SS gets TONS of attention from the ladies.