Tom,

I'm not sure I would go for larger intake valves unless you plan to race
your engine. My understanding is that the smaller valves increase
turbulence at low rpms which homogenizes the air-fuel mix. Can anyone
confirm this theory?

Rebuilding the engine yourself is a big time committment and spending
$4-500 on labor is easier in my opinion. If you want a quality job, though,
then you may be better off doing it yourself. Plus you'll get the chance to
do more than just replace the heads: clean the engine compartment, treat
rust, repaint the tin, replace all gaskets, fuel injector O-rings, *fuel
lines*, etc.

I think you said your compression figures are good and even, so I wouldn't
necessarily change the piston rings. As David Schwarze told me: it's a
whole new can of worms (things can go wrong, jugs must be rehoned, too,
adding to the cost, then oil consumption will be high at first and frequent
oil changes become necessary). Just make sure the cylinders do not separate
from the case when you pull a head or else dirt will slip twix case and
cylinders which will cause leaks. If that happens, you'll need to pull the
cylinder, too, to get to the gasket and it's a pain to put back on, with
the rings needing to be compressed, etc.

Sami