Besides originality, the T/A & AAR blocks had thicker webbing to help relieve heat build-up and keep the block more true at higher RPM's. Who knows, maybe the bidding war is a result of the owner of the car this engine belongs to. Numbers-matching engines in these Trans Am Series cars really help with their value. I've seen too many true AAR's and T/As where they've slacked and put 318's under the hoods because the 340's were too hard to secure.
