how much of a change in fuel ecomony can i expect going from a .422/.444 lift 204/214 duration cam to a .462/.469 lift 218/224 duration cam? i don't need exact numbers but about how many miles per gallon? i don't know what i'm getting right now, i just put on an edelbrock 600cfm tonight from a q-jet(wasnt working correctly). i want good performance but dont want to sacrifice to much fuel economy.

 

I have a Comp Cams XE-262-H cam, 600 cfm edelcrap electric choke carb and some other junk......only thing that might improve fuel effeciency is the Jacobs Pro-Street ignition.

I get 15 to 18 mpg, but I have like no stop and go traffic b/c of where I live. Lots of highway driving.

EDIT:

I didn't read your signature until now. I have the original L69, 305. If you're running a smaller engine you should get better milage than that. I can't guess what your drop will be, but you should still be pretty decent.

 

would it be like a a few mpg or a lot? about how many mpg do you think?

 

With my setup I was getting 18 mpg around town, stock.

With my mods I'm getting 15 to 16 around town.