Hello Bryan,305/45 drag radials on only a 10.5" wide wheel is giving you the floaty feel.
Toe-in will help the rear stay in line though.
I would like to take some camber arm too actually, for reach -1.5/-1.2 i have hks lowering springs so if you reach 1.8/9 i should be able with adjustments to go near -1.5 i guess thanks to my toe armI am lowered on Swift springs and rear camber is - 1.8 to - 1.9. I am debating Megan adjustable rear camber arms to get closer to -1.2 or so to help straight line traction. With 420whp & stock tires 1st & 2nd gears are spin City.