One other option on the rear shocks is to get a set of Chuck's brackets that allows you to use Mustang shocks so you have more options. From what i understand Chuck doesn't make them anymore but these guys have been making them off his design: https://tbirdcougarparts.com/
I am curious about the distributor/tif/pip too. Just for S&G's run a temporary extra ground cable to the coil and if that makes no different maybe move it to the EEC and check. I don't know how these ECM's and coils work. Is the coil hot the entire time and only controlled by the distributor or is the voltage increased by the computer for the load parameter?
I'd be curious to see what the ignition spark/wave looks like on an oscilloscope (Sun Performance Scope?). I never used one but remember the mechanics using it to chase ignition problems to see if it was only one cylinder and what was happening.
I put the Motorsport Plug Wires and the new couplers with better clamps on the in & out of the intercooler. I am still waiting on the cap and rotor to arrive. The old bottom coupler out of the turbo to the intercooler was so loose that the clamp did nothing. Checked the cam timing.
Although it was raining last night I wanted to know how it was running. No breaking up and runs well (flat ground).
Took it to work this morning (about 35 miles). Had a long hill to test 3rd gear under boost and the only thing to happen was the rear wheels broke loose.
I am going to wait until winter when I take it off the road to check the vacuum lines and do a pressure test on the boost system.