When that happened, you directed the flow over the ST better...it's not too large. Also, raising the roof AND filling the floor will pick up flow...AND lose power! You have to know what changes you make in the ports, how they affect power. Unfortunately, it's not always a gain in power with a gain in flow. That's where the bench gets very misleading...
When we used to sell the EQ and Indy heads, we were privy to a bunch of data from both heads prepped similarly as well as ported on street strip builds, mostly 408 cid engines...Indy's always made more power, most likely due to the intake port dimensions at the short turn. Never lost HP or TQ with those over EQ's...I asked Russ if he'd considered making the X heads in aluminum, which to my surprise was a yes...but it never happened.
OEM Magnums can make great power with porting like this. It's just really impossible to get high lift from them with water under the spring pad...that was THE key to both the EQ and Indy heads...we ran most of our builds with at least .605 lift, netting at least 500HP on mild pump gas builds. Fun Fun!!