Is that heat that it shows in game? Or on Coriolis? Because I find the resting heat thing on Coriolis isn't accurate. My Krait for example rests at 27%, but the build shows 46% on Coriolis.

Not a whole lot of ways I can see to drop heat. Your build shows Drag Drives, but you changed that to Drive Distributors right? That cuts some heat. Maybe swap Monstered to Thermal Spread on the PP?

I don't really understand how heat works. I read once that the PP doesn't actually produce heat, but is a sum of the all the power it needs to produce to run all the whizbangs. If that's true (and I don't know if it is), perhaps just dropping the power requirement will drop the heat. For example if you were to start swapping some E boosters in, that alone could make a big difference (and net a lot of speed)

My Courier rests around 30%.

Animals flee this hell, the hardest stones cannot bear it for long. Only men endure