It is hitting on the front six bolts of the jet intake?
What type of engine mounting system are you using?
How deep and what style was the pan on the 454?
Try installing short jam nuts and trimming down the bolts. Of course, be careful not to let the pan contact the bolts, they will quickly punch a hole in the pan.
The 8" pan plus gasket should fit. Some oil pan manufacturers 8" pan is really more like 8-3/8" plus gasket.
Cheers,
Joe
P.S. Wow, aluminum rods?!