Wow, that's a stretch. I'd like to see some dyno sheets for that comparison. I wouldn't compare HP numbers between a stock 273 and a 318 Magnum without some dyno time it's skewed numbers just to guess what a 273 with Magnum heads would do. The Magnum heads are not that much more and not superior to a 273/318 head. Not much different than a #302 head which isn't much different than a say #920 head. There are flow numbers floating around here somewhere. If I didn't have anything better to do I would look for them. What ever you think.
