I bought a 7R case with crank and rods for my RS project. The strange thing is that the engine number identifies it as a 74 911 engine (6144xxx), but I cannot find an engine type number on the case. What I did find was a casting number on the case 15/79 which would mean it was produced at a much later date (week 15 1979).
On opening it up it also has the 76- oil bypass and oilpump (four ribs as in wayne's engine book). It has the new pistons, but both springs are equal length and the bottom one does not have the sleeve.
It also features the later main bearing orientation.
What could this be, perhaps a replacement case installed in the car after a rod went through the case?
I all I am very pleased with my purchase as it is in great shape and saves me some cash and machine work for the oil pump upgrade.
