The new cam should work well, not sure how much of a difference it will make as both cams are very similar. The biggest improvement you'll notice will be from the higher stall converter.
Changing the intake to a single plane like the victor jr will help upper rpm horsepower a bunch over the dual plane, but it will kill some torque down low. If you go the single plane route I'd go with alittle more gearing, something like a 456 or 488 would be a killer choice for a heavy car like yours and coupled to a single plane intake, you would notice a profound difference in acceleration, however down side is that it would be wound up all the time on the street. I know your limited to camming due to your lower compression for pump gas and streetabilty but bumping it up to about 11 to 1 or 12 to 1 would really wake up your car espcially with a more agressive cam. You have some killer heads already, just missing a couple keys ingredients for a monster engine. I.E< compression, cam.
I know your caught between a rock and a hard place wanting streetablity, and not wanting to get into the expense of having to buy race fuels and then wanting it to be fast at the track too. I know the feeling.
Sorry for writing a book here, first post of the night for me and I'm killing time here at work so there you go. I seen you hadn't had any replies yet so I chimed in.
Goodluck with your new combo, Charles