440 pounds sounds like a lot until you look at the entire picture:
Pirelli P-Zero (2@245/45ZR20 load=1929lb, 2@275/40ZR20 load=2094lbs) = total load capacity = 8046lbs.
Yokohama Parada Spec-X (2@245/45R20 load=1709lbs, 2@275/40R20 load=2094lbs) = total load capacity = 7606lbs.
Camaro GVWR: 4551 lbs (2144lbs front, 2407lbs rear).
As for the speed rating, Spec-X is V-rated (149mph), P-Zero is Y-rated (186mph). Top speed in the SS is governed to 155mph and as we saw this weekend in another thread, you may have other issues at that speed too.
All I'm saying is that specs are specs and you should buy what you feel comfortable buying when it comes to tires. If you are going to be doing top speed runs, then spend the extra money for the Pirellis because your life will depend on it. If you are like 80%+ of the typical Camaro drivers out there, you'll never go over 100mph, let alone 149mph so you can probably get by with the Spec-X tires and have an extra $1k in your pocket (Spec-X set price=$558, P-Zero set price=$1610) plus nearly twice the treadwear rating of the P-Zero (Spec-X: 420A A, P-Zero: 220AA A).
