Car came back from the exhaust shop yesterday and I've got it running okay, I haven't been game to stomp my foot yet, once I have the laptop hooked up to the distributor and I can see real-time manifold pressure I'll do a power run. It does drive though!
It was also leaking coolant from the intake manifold, and I was thinking I'd have to take the manifold off and add RTV or something to make sure it seals, but it turns out I did not have the front two manifold nuts torqued correctly, so now it appears to seal just fine.
There seems to be an issue with #4 spark, disconnecting the spark lead doesn't change the engine's idle, but I do see sparks jumping to the lead if I hold it right up to the distributor, so the power is going *somewhere*. I've tested all the parts individually and everything seems to be okay, but the leads are pretty old now so I've ordered a fresh set just to rule them out. #4 also has an insert to fix a damaged plug thread, but I've had that repair done the same way in the past without any issues so it's probably not that.
The exhaust is a 3" downpipe into a 2.5" system, single muffler and a resonator. I didn't have any of the rubber band mounts spare and they're pretty stretchy anyway so I told the shop if they had a better bracket to swap them out. The one pictured below is originally from an Audi I believe.
