mileage after upgrade

[luiss666]

Hi!
My question is:
When I put into my 1981 Caprice witch SB350 something like this:
-edelbrock manual carburetor 600cfm
-edelbrock performer manifold
-edelbrock performer camshaft
-1 1/2 headers
-some porting work in heads
-three angle work on valves
-open flow mufflers
then torque & power will increase but what about mileage?
my wallet will be colapsed into black hole on gas station?
some own experienced opinions?
(sorry for my bad english)
luiss

[astroracer]

Milage is a derivative of efficiency. The performer series of mods are geared more to low end/mid-range torque rather then high end HP. Building your 350 as you have is going to improve efficiency and, with the performer based mods, you should see an increase in low end torque.
What this means is you should see an increase in mileage IF you drive the car sensibly and can tune the carb to run more on the frugal side. Low end torque is what actually gets the car moving and having more torque means less tip in of the throttle to do the same amount of work as when the motor was stock.