I see these two drawings floating around the internet a lot, presumably from the GM build books. But never once have I seen anyone mention the fact that the dimensions don't match.





Can anyone with an engine laying around take some measurements and let me know if either are accurate? I'm surprised I am apparently the first to notice this.

 

Something is completely whack or there is more than one block pattern. Here is the pink GM block dimensions overlaid with the red unknown source transmission pattern. I ignored the trans center point and lined them up using one of the dowel holes. The other one doesn't even remotely align, neither does any of the rest of the holes.

 

OK, well here's something. If you rotate the questionable pattern 10* on the dowel the top half holes line up. The bottom half are all still off though. So I guess the trans or engine could actually be cocked 10* to one side in whatever factory application someone copied these from?