Here's the upshot, if You don't want to pull the heads to have the guides shortened(I know...there ARE other workaround methods possible but), stay .475" max design lift. Wide LSA's improve driveability/idle which are more effective on higher durations. As already posted by others, keep the @.050 around 220deg max on the intake. The older cam I referenced had a smooth...read not aggressive.... profile, this makes it easier for the valve springs to control the valves, which are relatively light in a teener. Mine would start to "give in" just past 5,800rpm, so that's where I'd bang a gear. That 318 was out of a '74 Dart, I believe it had 78K(?) on it. Extreme Energy Hydraulics are great cams, but You will need to get the rec'd springs for sure.