To quote the old adage: "Speed cost money; How fast do you want to go?"
So there it is Jason; how fast do you want to go? Are you willing to do what it takes?
Since you started this build, engine and car, and then posting of track results, you have been given A LOT of good information, a little you have used and a lot you have ignored. It had been mentioned that your iron heads would be a choke point, and now you are coming around to that realization. 2.02 valves and 1.6 rockers may help, but they are not the "fix", they will be a band-aid. 410 cubes want air flow, especially when you keep the tac closer to the red line than idle.
One other thing, ET reduction isn't always tied to more horse power, the chassis has to be able to manage the hp put into it.
Trap MPH tells you hp you are making, ET tells you how well you are using it.