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Re: B vs RB Specifications

From: Adam Green
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Date: November 03, 2002


Rich, If you have the original engine in the car, it's almost certainly a B. Chyrysler introduced the B in 1958 with sizes of 350 and 361 CI. Ways to identify the B are, a deck height of 9.980" and a bore size of 4.06" (350ci) and 4.120" (361ci). If you have a 383ci the bore would be 4.25". All these engines have a stroke of 3.375" For the low block engine, there is an I.D. pad situated to the left of the distributor as you look at the front of the engine. As far as the RB engine goes, this has a deck height of 10.725" and all engines have a stroke of 3.75". Confusingly, there is one RB 383ci with a bore of 4.03". Other bore sizes are 4.1875" (413ci), 4.25" (426ci) and 4.32" (440ci). The I.D. pad on an RB is at the front of the engine to the right hand side of the distributor. The pads contain all the information on the engine such as year of nmanufacture, size etc. All this info comes from the HP books Big Block High Performance by Chuck Senatore. This book is well worth the money if you are contemplating a rebuild. Adam


Last changed: July 19, 2018