I have not worked on any Hemi engines and I'm not too familiar with the part #s. B and RB are the abb. for B block and raised B block. B=440 and RB= 383 and 400. When the blocks are bare the 440 will have a tab and 383 and 400 will go straight across the front where the front intake bar bolts down. I hope someone can chime in who has expierence with the Hemi engine and knows where to find the #s you need.