Flywheel sensor and timing question

[bitofaclue]

Further to my previous thread about swapping the new 4L into the '87 GC auto:

I want to make sure I'm not about to get into some ugly trouble here.  When I transplanted my old flex plate onto the new motor I think I positioned it the same with respect to the extra hole in the crank flange, but I didn't really put any effort into understanding why.  Now that it's all bolted up it occurs to me that the irregular spacing of the holes in the flex plate ring is probably feeding not only speed but position information to the computer.  Is this the case?  If I got it wrong is it going to totally screw up the timing and force me to lift this motor again?

Thanks.

Jonathan