What about overboosting NA blocks? I have a Giles pump and it will be running 15psi for sure...would the extra cooling oil would be good for longevity?I know VW made mark2's in Brazil Africa and China well into the 2000's but I assumed all mark2 diesels (up to '92 produktion) came from Germany. All VINs Ive seen back that up but obviously I dont know for sure. I can check the crank itself.As for the blocks, they all seem to get the ring wear in the bore and leave a nice lip at the top, between deck and top of piston stroke...it seems to be more pronounced on boosted motors? Anyway I assume the bores should be enlarged when starting fresh..obviously the ring end gap is slightly bigger but also the rings dont sit as deeply inside the piston grooves...i assume this is a good pathway to loose some compression/blowby.