That LF wt has me scratchin my head...slicks are moot right now. A real hot burnout or VHT would be a "fix" til you sort it out. You moved the right bar...made it shorter by looks of things. I assume the wheelbase is right on the money.
Still, LF makes it look like a handful at the other end (on paper at least). Once you get the new boots on it any mis-adjustment will show up big. Sounds like a fun car. Pinion angle looks good to me.
I'm throwin in wrinkle here...Your bars, are they up, down, or level at ride ht standing still? Heres the reasoning...Look at the bar as a lever arm and picture the arc of the rear axle as it travels say 10deg up, then 10deg down from dead level (a pencil on a flat surface helps the visual here). So if the bars are level, on launch the wheelbase wants to "shorten", and this is exagerated if the bars are in the up position before launch.
If the bars are down from level at ride ht ready to launch, On launch the wheelbase wants to "lengthen" and thereby softening the hit just enough to do the work of planting the tires. How much does it lengthen? On my car, bars down 1 hole from level, raising the car (bars) to level from the ladderbar Xmember, my wheelbase extended just under 1/2".
So what? So then the car is, in a sense, moving forward before it rolls forward, while the bars are doing their job planting the tires. Vehicle reaction time improves. Launch seems less suitable for hollywood action flicks but remains consistant. Since the tire cant go "down" on launch the body comes "up" changing the level of the forward mount on the ladder bar.
Bars up=hard hit, violent launch, bar tries to shorten W.B.
Bars down=softer hit, less violence, bar wants to lengthen W.B.
Try the pencil thing. The point is your mounting bolt. The eraser the axle center. At level length "x". Up or down length "y". Launch at "y" with point down, you end up at "x". Launch at "y" point up you bind or go "shorter". Something to schmooze on in your head. Hope it helps.