On the other news. I received my new wheels (Apex SM-10 18x10.5" +22mm) to run 315/30/18 RRs. As I already had a spare set in 295/315-30-18, I decided to use the 315s out of that set and post the 18x10" wheels as well as the for 295 tires for sale.
I had them mounted and balanced at Chase Race and test fitted them after I came back home. Long story short, it's a tight fit but seems to be working . I am so glad that I let Doug to grind and weld the knuckles a bit further to gain some extra space. Combined with the -2.7 camber , it will work. For the reference, the chicken strips on the sidewall don't touch the knuckle and they're at least 5-6 mm long. I still keep my 3mm spacer and can combine with the existing 5mm spacer to make it 8mm (as I already have longer wheel studs) but it looks like it won't be necessary.
I also changed the differential after the first track day. It didn't seem that bad but I also couldn't really drive at last event that long too.
Also added the brake deflector and it looks huge compared to the OEM SS 1LE deflector. I am hoping that they also make a difference for cooling the rotors by looking at their size, I can guess they're very functional. I cannot believe this part is only $15, perfect fitment as expected from a GM OEM part and good quality