Driveline loss
Which setup is going to give you greater drivline loss:
6 speed Y-body
6 speed F-body with a 9"
I understand that IRS is pretty stingy.... but but how so in relation to a 9" on an f-body?
The transmission/transaxle location of the Vette, as well as the shorter path
to the ground and rotating assembly weight.
The IRS suspension is said to be less desirable for launching the car...however
I've seen some pretty nice 60 foot times from stock Vettes that makes it all
seem trivial.
IRS does have some drawbacks for a launch versus a Live axle. When you transfer weight back under acceleration, the camber of a live axl will stay about the same on each wheel. Meaning you have each rear wheel strait up and down even under a tail dragging nasty launch. The IRS on the other hand will produce negative camber when the tail end squats under the weight transfer. This means that not all of the tire is touching the tarmac.
But a nice stiff suspension and good bushings really helps to minimize this problem, as evidenced by the mean Vettes out there. In extreme cases you could even get an alighnment that has a touch of positive camber normally, so that under a lucnh the tires end up strait up and down. That would hurt handling though, which is why you get IRS in the first place.

