Dumb Question, yes?

The 361 thru 400 original blocks were "B" blocks 413,440, and 426 were "RB" blocks these were all considered " Big Blocks". The RBs were taller and wider than the "B" blocks. Even though Heads, valve cover, timing cover oil pans etc would direct interchange between them. The cranks and rods were different as far as journal size rod length etc. From what I remember even the 426 hemi heads would bolt to the other big blocks, but ( and this is going back 30 years so may NOT be 100%) had to have push rod clearance machined into the block. Someone at one point and time it seems sold a kit to bolt them to 440 blocks. To me the 5.7 hemi is more closely related to the earlier hemis (392) which were considered "small blocks". But with all the stroker kits today you can take an A block (small block) and achieve the same displacements as the "big blocks" from the factory. With this in mind these strokers utilize the same block whether A, B, or RB which in turn gives you the same external dimensions of the original engine. This thread may help answer some dimensional questions. http://www.forabodiesonly.com/mopar/showthread.php?t=228120