Multiple messages required by length limitation & will make more sense if read in reverse order. I ran a 11.799 with a 1.675 sec. 60 foot last night with new rims. There may be another .1 reduction still there..
I felt the 40 lb less weight w/ 25/26 lb OZ rims & they took .2 off ET plus 3 mph top end. Got 40 lb more off w/ SSR rims, 16 lb. @ (mostly in the front w/ lighter tires) No ET change except 60' change. Better handling, mph same, due to shorter tire maybe?

TIP these are BMW rims. Bolt pattern same 5x120mm. Vette rims 5x4 3/4 (5x115) Hard to center with spacer,some need dremel work, after markets loose enough to fit may not center, may loose lug nut.
BMW 300 series correct offset. stick close to stock. The M, Z & other models stud (114mm) but some 112mm. Fronts 114mm & OZ centering hub rings and lug nuts (smaller than stock) worked perfect. Rear stud holes for 112mm are tight but no centering issues for 3/8 spacer (best price Speedway Motor sports, billet aluminum $11.99 @
TIP: Tire Rack lists 144 rims for 2010 Camaro LT not other models. 46 of these on special. 18" wheels cheap but hard to find in a 9 or 10" width. Maybe get rears elsewhere to match? A half inch under recommended minimum rim width for a tire Ok but my limit. 17x9 rims under BMW &18x8's under Camaro LT. Got $2400.00 rims for $400.00. All you see is rotors.

I got two 17x9 & 18x8 SSR 16 lb. rims from Tire Rack. $99.00 @ on clearance when there are 3 or less. Black rears & anthracite fronts. 17x9 needed to run a 295/45/17 MT ET. 1" more shoulder and 1" more tread vs. 20" Nitto 275/40/20 DR's. New Nitto NTO5 DR, softer w/ dual purpose shoulder should be a better DR
18's perfect on front and 27" tall tire easy to match the rear 27". (necessary for ABS) More street than skinny but saved 10 lb. @ over stock. Rear MT's not lighter. Rear one piece OZ rims showed 3/8" clearance if reduced to 17". But two piece SSR front's smaller with wield to a larger wheel base. Had to grind the outer and front of the calipers to get the 17's to work with a 3/8 spacer. Tight fit so not noticeable even with 20" OZ's. An 18 would fit fine on the back but I wanted the 17" MT to get the 1 & 1/2' reduction over stock diameter. Still runs same mph in 1/4 mile but quicker. Primarily due to improved 60 foot. Been advised a 4.10 rear end may not improve ET.