I have a 2000 B&B with a 427 and to answer some of your questions:
Brakes: Fronts are probably GM Metric(78-80 Monte Carlo), Backs 87 Lincoln Mk VII as is the axel if it is a solid 8.8. I switched mine to dual piston Wildwoods.
I had a custom radiator made for mine by Arts Radiator in New Jersey ($450).
I am running a Canton Road Race
oil pan ($350) and I have between 3 1/2 and 4 " of clearance. Hasn't been a problem yet.
Clois