it's not the hp that's necessarily off, to me it's the torque, unlike hp torque very tied to displacement generally a performance engine goes from 1.1 to 1.7 lbs-ft per cid, 1.5-1.7 is highly developed nascar pro stock etc... not your average build. If your getting over 1.2 your doing good over 1.3 is extremely good, 1.4 is pretty high and above most builds. And if this build is 1.4 lbs-ft per cid hp seems low for that level of a build, to me the dude grabbed a dyno pic that he felt would fit, my guess it's more likely a mild ish 420-450 cid engine dyno chart.