What MPG are you 340 guys getting?

Old thread but I thought I'd add my input. Currently running a warmed over 340, mild cam aluminum heads etc. My biggest change was adding a holly sniper. I have 392 rear and a torque flight 727. I'm lucky to get 8 miles per gallon. I think that the sniper is adding more fuel than it should. But my spark plugs look clean. I'm hoping that once I swap over to a Tremec 5 speed I'll see a little improvement on MPG.