So what did they do regards the engine number Ron? New number, or stamped the replacement block with same as original then destroy original? My VX Clubby had engine replaced, it's marked in the log books as replaced engine, but the log books show correct engine number. I bought the car in June 2006, it was originally sold and first registered in April 2001 (October 2000 build). I believe with all the issues with early LS1's that Holden had replacement blocks stamped with same engine as original, then destroy the old block.