If you emailed recently, I'm sure they are preoccupied with this years event, which starts today. Power to weight ratio should get you to the 8.50 limit. You'd also be running against Scott Miller, provided he attended, in a field entirely dominated by GM's. And nobody has really pushed the 8.50 limit, that I'm aware of.
If no fiberglass bumpers are to be had, you can shave a lot of weight by removing the heavy steel backing and ditching the "crash" mounts. It wouldn't be hard to fab some lightweight brackets and just keep the aluminum front.
Wheel tubs and frame notching are also allowed, so a good size tire would fit, keeping within the 11.5" limit.
Good choice on the car and class. Good luck.
I did that with a 78 Futura years ago,I pulled the bumpers off and removed the impact beams from them and reinstalled the aluminum shells,it was a long time ago but I don't remember having to fabricate anything,I left the shock absorbing mounts and if I remember right there was a light stamped bracket that the impact beam and the shell bolted to seems like I just ditched the beam bolted the shell back to the bracket which bolted to the shock absorbing mounts and done, but I suppose you save a few extra pounds if you fabricated pieces from aluminum to replace the shock absorbing mounts and the stamped bracket.