i have a small block now. i think im going to stick to a standard deck big block. it doesnt seem worth it to me. i mainly drive mine on the street. i think a standard deck 540 will do fine. but the heater core and the cover on the fire wall.
WITH A TALL DECK? I bet ya have to remove or heavily modify the core cover as with the stock BBC mounts moving the engine over 1" to the passenger side and then the heads spread and raised a good 1/2" in both directions... you would never get the valve cover on the passenger side.. let alone get in on the booster side.