Thanks Cole.

One other thing for simplification that I was looking at the other day -- was to run the front and rear heat exchangers in series, rather than in parallel. This would allow the removal of some T-junctions and the flow control valve. I figure the front heater core performance won't be affected, and the rear core already seems like the weaker of the two - so it would clean up things quite a bit. One hose from the back of the cylinder head to the front heater core, then the return line goes straight down to the hard lines for the rear heater and then back to the recirculation inlet on the thermostat housing.

Another thing I looked at -- but its more for those who don't drive in freezing temperatures, is that the throttle body coolant line (which heats the throttle body to prevent freezing up) can be removed. This would eliminate and clean up the coolant lines as well - eliminating another couple of T junctions. The return line from the throttle body is pretty ugly -- just a long 3ft hose that drapes over the engine. One other option here to clean this up (rather than to delete) -- is to route the return line (off the TB) back into the front heater cores' return line. Not as clean, but certainly more elegant and retains function.

Itsamoto - love that idea, and just wanted to follow up on this to see if you have tried this setup. I might give it a shot here soon, as I am about to replace the upper coolant pipes and crossover/crack pipe.