For reference, I just measured 2 here in the same fashion:
- 273 block - 7-1/2"
- 360 block - 7-7/8"
The one deeper down, in the 360 block, was above the oil passage to the filter by 3/8". It was driven in with the cup 'down' (with the flanges were down).
There is nothing critical about how deep this step is, and it may not have been critically set when originally drilled. And the plug may not be driven home all the way. Plus, if the plug is driven in with the cup 'up', the measurement from the pressure sensor hole is going to be deeper by around 1/4"-3/8". So, I don't think that any of these numbers listed in this thread are going to be exactly repeatable, block to block.
