According to the post Tube Rolling w/Crack (which has been read 230,518 times; an amazing number) the 12BH7 is "Sort-of-a-Drop-In (but not equivalent - for best results, replace plate resistors with Speedball boards)". It just means that the 12BH7 will work but may sound better if one installs a proper valued plate resistor. I have had no problem tube rolling and listening to the 12BH7, very nice sounding tube even without changing the plate resistor.
I have considered installing a switch that would allow the use of the stock and 12BH7 resistor, but didn't think it was worth the effort, the 12BH7 can be an extremely good sounding tube in the Crack.