I have a 340 and I can say it no way makes 350 horsepower even thought its not stock. I think the 275 factory rating is pretty accurate for a totally stock engine.
its not there is a reason nhra rates it 300 to 320
a blueprinted stock 340 makes 340 its been proven over and over again
Really dont see how someone can be on here 15 yrs and think it makes 275hp