This information from the AllPar site: Big Blocks There are eight different big blocks. The B blocks are short deck and the RBs are tall deck. The RBs require a wider intake manifold.B: 350, 361, 383, 400 RB: 383, 413, 426 Wedge (not Hemi), 440All B engine use 3.38 stroke crank with different bores, and all RB engines use 3.75 stroke crank with different bores. You'll notice that the 383 is listed in two differnent places. There were two different 383s; the RB is very rare, only produced in 1959 and 1960. The 350 was only produced in 1958.Frank McMullen added: “I own a 1960 Chrysler Windsor, equipped with the RB-383; while the RB 383 was offered only for the 1959 and 1960 model years, according to production numbers offered in Std Catalog of Chrysler, some 109,000 Chrysler Windsors and Saratogas rolled out of the factories with the RB-383 engine. There were no RB-383 engines after the 1960 model year; the 1961 Saratoga used a B-383. I discovered through research that the RB is essentially an "underbored 413" (although it did have different cores and water jackets... so one cannot simply take their RB 383 and "just bore it out" to use more common B or RB pistons).” I have a RB383 engine in my 60 Chrysler Saratoga. Good engine. A lot of potential for bore modification. Larry (Akron) -- [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html. This email was sent to: arc.6265@xxxxxxxxxxxxxx http:///u/?.. Or send an email to: 1962to1965mopars-unsubscribe@ http:///?p=