-stronger
-more reliable(apex seals... cough cough)
-has TORQUE
-better fuel efficiency
-doesn't NEED turbos(and if they are ever added it will wipe a TT rx7's ass with a rock)
-not sure about easier to work on, but it sure as hell is easier to find a technician that can fix it if need be
-cheaper to make it go fast
the only negative I can think of is that the RX7s are super smooth, so I suppose if you can't stand a loping car then get over it and stop being a puss.
Yes RX7s can rev to 9000rpms.. but in reality the engine doesn't START until like what? Maybe 4500 rpms? The LS1 has a torque curve that gives it insane power from about 2000 rpms to redline.
And no, just because it has the "inferior" pushrod design does not mean it cannot go over 5000 rpms With a decent selection of valve springs and rocker arms it can see well over 7000rpms. The fact is it just doesn't need to