[Supras] HELP: Weired piston height

[berniek at technicaldevelop.com]

Man, if I ever needed help from knowledgeable people in this good group, 
now is the time.

I got the head off my newly bought '91 turbo to lap the deck and install 
a Cometic gasket and rebuilt head.  While cleaning the piston crowns, I 
noticed that the first cylinder piston crown is about .100" lower than 
the others.  Measuring it and piston 6 to the deck, the .100" additional 
depth is always there!.  There is no vertical slop indicating bad 
bearings or a bad wrist pin.  That was tested by turning the engine over 
to pull #1 piston down in the bore, and then tapping down on its crown.

All of the bores are just about at the factory initial size (3.270" 
measured with an inside micrometer.  #1 piston crown looks fine.  All 
are stock turbo pistons.  There are some very light scratches at the 
backside of the bore but no top ridge in any of the cylinders. 

This is the weirdest thing I've ever seen.  Is there any chance that it 
was assembled with a piston or rod from a different year?  The engine 
ran fine before disassembly.  Any and all suggestions would be very much 
appreciated. 

       BernieK