Thread: Rebuilding a 292 for mpg

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Good point. Something like a 390 Holley. What about increasing the size of the exhaust valves? My thinking was that it would increase the volumetric effieciency which would help with mpg. I'm just taking a guess on the cam.

valve size increases dont always help... you might be able to get away with going a little bigger, but truly bigger valves wont help much.... going lighter will get you more improvement on the engine..... lighter valves are more expensive... but they help..... they get pricey though.... i spent $400 just on valves when i did my heads because i wanted to get them as light as possible