I am getting to the point on my 69 RS/SS that I need to put a radiator in it. I am looking at the 4 core from Ricks. I was wondering if I can put a 23" bb 4 core radiator if I buy the bb shroud. Right now the car has no raditor or shroud. Will there be that much difference in a 21" sb versus a 23" bb? Also will I have to buy the brackets and such for the bb if I do this? The car originlly came with a sb in it. Thanks for any insight.