With proper offsets, you can absolutely put a 19x11 in the rear.
I run 19x10 at all 4 corners 35mm offset.
Going to get a pair of 19x11 50mm offset to match. Lots of pics in the wheels and tires subforum to look at.
I have power pack 2 as well. Drive modes still work. Maybe try disconnecting the battery. If that doesn't work, l would suggest flashing back to stock, then re-flash the tune.
Ordered SVE R355s in 19x10 titanium gray from LMR. Also ordered BMR CB762 bracing and adjustable end links from Lethal.
Waiting for Cyber Monday in case Steeda pulls a "But wait, there's more!" gift add on like last year before I order the tension arms and roll center correction kit.
I went with a McLeod RST with steel flywheel when my stock clutch went out. Check with Beefcake or Lethal, as the clutch/flywheel kit is on sale at both.
Had some parts installed earlier this week, first chance I've had to drive the car any considerable amount.
BMR poly vertical links
Steeda differential bushings inserts (street)
Steeda RLCA bearings
FP knuckle bearings
Steeda tri-ax race shifter.
Acceleration on upshifts is much more direct...
Strokerswild, I built a 260 Remington on an Aero receiver set. An SLR Rifleworks adjustable gas block fits under the m5E1 handguard, and is click adjustable using a hex wrench.
Armorally.com has your lower in stock for 133.20. I've purchased from them in the past and they are GTG.