On my 79 Cordoba, my goal was to keep it original looking. I had a spare Lean Burn box, gutted it and cut the bottom to add clearance for the orange box connector. I cut off the old Lean Burn ECU plug off the circuit board and soldered to the pigtail for the electronic ignition. All the wiring needed is in the factory wire to the lean burn.
I was concerned about heat, but I think the high volume of air moving around keeps the orange box cool enough. This was done 20 years ago and I used to use the car pretty much every day back then. In theory I could swap back in another lean burn module and old distributor and go back to stock, not that I want to.