That's what everbody says. Would be interesting to put it on a dyno.
I have built a 260 for more power and a 347 that does make 450 HP. Spent lots of time with the 260 and 347 on a dyno. The guy is flat out lying. There is no way a 260 with the extremely restricted head ports and small valves can get anywhere near 400 hp much less 473.
You will never see that car on a dyno because he does not want to face the reality of maybe 290 HP out of his 260. People who boast false engine power numbers really piss me off, can you tell?
Anyway HP dyno readinhs are as useful as peeing into the wind. Dyno should be for getting the mixtures and ignition perfect and getting the powerband useful... Dyno donkeys are useless on a track.
Who said it has original headsanyway it's big fun and feel invited to join us next year on Salzburgring track...