There's now a Volvo-sized hole in my garage.
After waaay too long being parked up, Tiago & I plugged the 400ft of vacuum hoses back and tried our luck.
Defying all expectations, she started first pop and ran like a dream. There's no more clunk in the rear, the intake actually has vacuum, and most importantly the heater now blows cold air.
With the rear now 3x as stiff as the front and still on stock shocks it's a little lively, but new shocks are slated for the rear shortly.
We pulled parts off a car, put them back on and improved it. Holy Crap... we must be mechanics.