Alright. This post is pretty much a, yes you can do it, post. Not really instructions. I just put the Marren PD on my s5 t2 block that previously was on my s4 n/a.

If you do not have a aftermarket PD then Clousbourne (I think I spelled that right) has a post in archive about what parts and adapters you need to buy in order to retrofit an aftermarket PD on your car.

https://www.rx7club.com/2nd-gen-archive-72/marren-fuel-injection-fpd-retrofit-writeup-356838/

To swap the PD over to a s5 t2 you can use ALL the parts from installing on a s4 n/a. There are no extra adapters needed. (Hooray!) Now you might be thinking, how can I use an aftermarket PD when the PD I have now is welded to the rail. Well your right, you can't use that rail, but the s4 n/a rail works in its place. If you previously installed the PD on your car all you have to do is swap the banjo bolt and the mm -> -6an adapter from one side to the other.
It will look like this:


(Notice how black and charred my primary rail is. It's been on fire before.)

You will HAVE to use the s5 t2 secondary rail. Remove the banjo bolt on the side facing the bumper and put the mm -> -6an adapter in its place. If you are swapping the PD from your s4 n/a setup, you can remove the adapter you already have from your secondary rail to put on the s5 t2 secondary rail. Next you will use your coupler and screw it down so it looks like this.


(You might be able to turn it to where the PD is facing towards the hood, but I thought this looked better.)

From here just reuse the -6an hose and connect the two rails together. Like so.



After this you are finished.

Here is a pic of the primary rail with the UIM on.


(It just barely fits, but is enough to get you on your way.)