340 actual horsepower

Does anyone know if an early stock 340 was independently tested on a dyno for actual horsepower? We all know that @275 hp was under rated. I remember when my buddies dad bought him a new 68 gts 4 gear for gradualtion!! He picked me up and that car would actually cause neck damage from the factory, they had high compression I think 10.5 to 1(i got drafted he went to australia). Everything i read today states that a cam upgrade with comp springs and -0- decking, air gap and you have 400 horses?

Just thought you guys would have your educated opinion for the world to see!!!!!!!! Walt :coffee2: