like the title. I would like to know how difficult it is to install these parts

I haven't actually done this mod, so I can't say for sure, but seems like it would just be one of those "unbolt the old one and bolt in the new one" kinds of things, right? I mean, they're a little bit buried in the engine bay, but with the right tools they're not all that hard to reach.

yeah, thats what im thinking. But im taking into consideration that on some cars, the motor has to actually be lifted, and/or critical engine components removed like the tranny or...something else that determines whether or not the engine will run.

or better yet, rather than the engine being pulled; all of the hoses and brackets and rails will have to be taken off. If it is a pain in the ass, i probably won't do it simply for the sake of the car.

Get the car up on a stand and have a look at how difficult it would be from underneath.

I think the Subaru is actually one of the easier ones to tackle being a flat four.

Yeah, so many people have done this mod that I'm assuming any idiot can do it.

I heard doing the up is a PITA, one guy said it took him 14 hours but im not sure if that’s the case with everyone, probably would be with me. I know you have to remove the IC if you go at it from the top. DP should be cake

if you do decide to do this mod, are both the UP and DP necessary or can they be installed solo?

im pretty sure you dont have to do both at the same time. i know when i do those mods im doing it one at a time because i dont have the money to do them both at the sametime

You can definitely do them individually if you so desire (or because of monetary restrictions)

You can definitely do them individually if you so desire (or because of monetary restrictions)

What he said. if your going to do the up the best IMO is a gutted stock or a STI up that way you get the less restriction but none of the leaks and you can find both cheaper than most aftermarket brands.