I may be wrong, but the current prostock engine is a further refinement, of the "drag race competition engine" that Warren Johnson helped develop with Oldsmobile. There is no connection to any production engine, not even Oldsmobile. Let's face it prostock is finished, NHRA is to blame. Warren Johnson said as much, a few years back. The best line was from Erica Ender's father , while being congratulated on her championship, " Yes, yes, thank you, it only cost me $23 million dollars" ! Wow