This main reason for modifying the tunnel brace relates to the fact I bought a turn key package of LS3 and T-56, and the T-56 is the f-body generation. My research, unfortunatly after the fact

, I came to the realization that the shifter is located much further back on F-body T-56's versus the aftermarket styles from Keisler or Hurst Driveline.
I used the car shop 1" set-back plates, and even reduced the set-back by 1/4" by re-drilling the plates. I didn't redrill just to avoid the tunnel modification, but was trying to eliminate the need for notching the frame as well. Didn't work obviously cause I had to notch the frame ever so slightly. Probably could have raised the motor a little bit, but that makes getting the driveline angles more difficult with a factory tunnel and the height of a T-56.
Another item I ended up having to re-address was the steering box hitting the Hooker Headers. Attempting to drop in the motor in for the last time I came to realize the headers were making too much contact. Contacted Frank and he set me up with DSE's 600 box. This netted me a little more room, but I had to dimple the headers still, but only a slight amount. Frank gave me a quick tip of using a large socket and felt pad between, then struck with hammer on the socket to create a clean dimple. Worked out great, and a big "Thanks" to Frank for the idea.