The cooling system design was a LOT harder than I anticipated.  How hard could it be, right?  Because I was determined to stay with the stock fuel tank location, I found that it was directly in the way of the coolant route from engine to underbody coolant pipes.  One thing I learned from past swaps is that you also want to leave room for your hand to get in to spaces between various components in the engine compartment.  Otherwise, you’ll be swearing at yourself when you’re trying to service something installed long ago that’s now totally inaccessible.

My solution was to give the pipes a detour over the gas tank then back to the engine, to give access to the clutch cable area.  I created a pair of SS extension pipes, which also served as mounting points for the dash gauges (water temp gauge and overheat light sensors) as well as bleed valves.

Below are stock reproduction SS pipes that I ordered from a race shop back East, modified to fit my application, with the pipes above before I added the fittings.

These two sets connect together with straight hose along the firewall.  For the connections to the engine, I bend up brake line to match the centerline of the hose path, and head to my local Napa parts store and comb through their stock area looking for radiator hose that matches my application.  It gets really difficult when both hose ends are different diameter, but I lucked out and found a hose that worked pretty well.

I added a fitting at the front of the coolant pipe that connects to the top radiator for the heater, saves a second run of heater pipe.  I then repurposed that heater connection on the engine for the coolant overflow tank.