Another thing to remember is that very few 20Bs were N/A in standard automotive use. The 20B will produce nearly 300 HP normally aspirated at less than 7000 RPM. Al Gietzen dynoed the 20B he put in his cozy and with a fairly restrictive exhaust it made 285 at 68 or 6900 RPM. With a 2.85:1 redrive and any slight flow improvement it would best 300. Another real plus is that the engine is not at all highly stressed at that output.
Bill Jepson 

Bill – excuse me; it’s a Velocity RGJ.

Al (not that I have anything against the Cozy)