Few Questions,
that's a beauty dart, i'd keep launching at higher RPM's until it won't hook any more, just trial and error you know. 3.91's or 4.10,s would probably help it out a bit. I've heard of people using lighter torsion bars like /6's with a small block or small block ones in a big block. I've also heard of guys taking every other spring out of their seats ( usually passenger and rear) to shed some weight. fibreglass front end would be great if you don't already have one? o and by the way that is one gorgeous car!!!