kh vs mc turbo engine differences

[Lines Peter]

To add to Ti's info...
The KH has a 79.5mm bore while the MC is 81.0mm  (a KH block can be bored
for MC pistons)
The KH and MC both have oil squirters
The KH uses cast pistons, the MC uses forged pistons
The KH has a 8.3:1 CR, the MC has 7.8:1 CR
Some KH engines have oil-cooled turbo, some later ones have the oil/water
cooled turbo.  Scott Mockry's site: sjmautotechnik.com has a really good
explanation of the differences in these 10v turbo engines.  Also, the KH
uses a Hitachi MAC-07 ECU, while the MC uses a MAC-10 or 11.  I'm not sure
about too many differences in the head, although I know the cams are
different (but compatible) between the KH and MC engines.
My soapbox is "don't give up on the engine just because it's a KH".  You can
easily give it the benefits of the full MC treatment.  Since you already
have the water-cooled turbo, you are halfway there.  Get an MC cam, and a
MAC-10/11 ECU.  This will basically give you a high-compression-MC with
slightly lower displacement.  Or... if you are going to rebuild the engine,
get some MC pistons and have the block bored to 81mm.  Then it will be 100%
MC.  I'm suggesting the MC pistons for a rebuild because my experience is
that the KH pistons are very rare in the stock size and nearly non-existent
in the oversizes.
You can connect the MAC-10/11 ECU to the KH harness by switching 2-3 wires
on the ECU connecter plug.  Look at sjmautotechnik for full pinouts for both
ECU's.  It will be obvious which wires to switch.  I'd be happy to answer
any other questions you have...  (BTDT)

Peter Lines