Chrysler's "B" and "RB" engine blocks are extremely sturdy. The block casting uses extensive support webbing in the mid and lower areas. The main bearing bores are supported by the block sidewalls which extend past the crank centerline more than 2 inches. Additional webbing to support the main bearing bores make the block very rigid without excessive weight. Bare block castings weigh in at about 215 pounds for the "B" engine and 225 for the "RB". The primary differences between the "B" and "RB" blocks are the main bearing bore diameters (2.625 for the "B", 2.750 for the "RB") and the crank centerline to deck surface dimensions (9.980 for the "B" vs. 10.725 for the "RB"). Rod journals are the same for both engines.

Interchange between the engines is exceptional. Both use the same 4.80 inch bore spacing and the same cam to crank spacing. The heads, timing chain, camshaft, oil pan etc. interchange completely. Intake manifolds don't interchange due to the difference in deck heights.

Cylinder Head Casting  (This is a starting list please send updates to Web Master.)