I think it looks ok... they are not sticking up in the air, which would look bad. The manifold in general looks way nicer than the process west unit imo.
It's a chunky bit of kit alright. I like how the video points out it will likely hurt performance down low and even into the mids... and only benefit big power builds up top.
Personally I think the vacuum block on the top is the best idea ever... my manifold has the vacuum block at the rear almost underneath
and it's a huge pain in the ass getting the hoses on.
Although, maybe he is correct. I thought he meant remove the centre diff permanently! I guess if you machine off the splines that drive the front diff and weld up the spider gears in the centre diff... it could work.
You can adjust the piston position at the top of the clutch pedal. Move it towards the firewall. You might want to check that the hydraulics are working properly first though.
Also make sure not to adjust it too high, because then, when you push the pedal to the floor it can over extend the clutch fork and the master cylinder.
There are different R180s too... I only have direct experience with the GC8 Type R/RA diffs that have clutch packs... the circlips are internal with these.
Some of the later STis have a viscous rear R180...pretty sure the axles are the same though.
It should be pretty obvious by the depth of the groove. A deep groove on the axle stub will probably mean a circlip is supposed to be present. A shallow groove probably
means the circlip is inside the diff. You can also put your finger in the diff and see if you can feel the circlip... should be easy enough.
There are quite a few different rear diffs on these. Some have circlips on the axle stub, and some have them internal to the diff.
Some have equal length axle stubs, and some have different lengths. Something only one side has a circlip on the axle.
Fuel enrichment when cold causing issues maybe? Or maybe the temp sensor is bad, so fuel enrichment is not happening.
There will be a bunch of things different in the tune when it's cold.
Expect to pay around 10k for a decent rebuild. Maybe 8k if you take short cuts... 12k if you do everything properly.
Removing the engine and taking off the heads will save a bit of money... but the costs just add up and up and up.
There are diagrams around... you just need to search for them.
It's very likely that Joker is correct though. Just a spare plug with some power going to it, so useful for some previous owners to hook into for whatever.