Get my car to launch better...

Don't I remember from the 70's and 80's that shock to use was from a "C" body? (Because it is longer?)
BTW, remember that just because your axle hangs "X" number of inches w/o the shocks attached doesn't make that the right length for the shock. Under torque, the springs could move even further.

I'm a little confused on the pinion angle thing. The 1980 Direct Connection book says to set the rear joint angle at 5-7*, nose down, using a stock spring. (The difference between the driveshaft centerline and the pinion centerline.) I believe the idea is to have as close to no angle as possible under torque, freeing things up. S/S springs require less angle, as they are stiffer, ladder bars even less, etc.
They also say to keep the front angle at less than 2.5*, on all suspension types. (Crankshaft C/L and D-shaft C/L, I have to assume, not specified in the book.)
I've had to set the rear angle in the past. I've never had to set the front, and don't remember ever checking it.
Is all of this the same as what you guys are talking about?

Juvat, what you're doing is the right way to make a car e.t. It makes no difference that it may be inexpensive.
Getting the most from the least is what make NHRA's Stock Eliminator cars so quick. Well, that's one of the things, anyway. ;-)

Oh, you might want to try some solid bushings in the front leaf spring eye. Depends on what "streetable" means to you. (They'll be harsher and noiser.)