Greetings.

I encouraged my 15 year old son to get a good project car in order to
learn auto mechanics.  He found a really great 1984 944 with 90k miles
and has been doing minor repairs so far.  School is out and we've
started figuring out what major work is needed.  We know of some pretty
big oil leaks at the front end and rear end of the engine and there is
some serious shaking at idle.  Last night we did a compression test and
got 200psi on all four cylinders.  200psi seems a bit high and I'm
wondering about carbon build up.  The plugs looked great on the
electrodes and insulators but there was a fair amount of carbon on the
threaded base.  You could see a lot of carbon peering through the plug
holes on the pistons.

Is 200 too high?  Is there any down side to carbon build up?  Is
pulling the head the only way to remove carbon deposits?

On other stuff, we are thinking of replacing all the front end oil
seals along with the belts, changing out the clutch (too much slop in
the drivetrain) and rear seal, changing out the engine mounts, and
possibly replacing the seals in the oil cooler as a precaution.  Given
this list, would it be easiest to remove the engine?  Any other advice
would be appreciated.

I've really enjoyed searching this group and look forward to your help.
Thanks.