Guys, I have a 87 s4 tII. Great shape, running fine. I also have a 90 gxl that I am wanting to do the swap. I have all the tools basically should only take a day. The only questions I have are, are there any necessary items, such as mounts, cables blah blah blah. I want to know if it is a direct swap. Please let me know. PM me. Thank you.

 

If your swapping long blocks including the tranny, the harness and ecu is all you need to swap with it, everything should fit fine.
If your keeping the tranny, things like the flywheel etc and whatnot on the s5's are balanced differently than s4's, so keep that in mind.

 

Isn't this swap info in the stickies???

You'll need the entire drivetrain, cause it's totally different from the NA stuff.
This means...
engine
trans
driveshaft
rear diff
rear axles
...all need to be swapped.

Turbo II ECU and engine harness required, but it's a pain in the *** to splice into the dash crossover harness for the 1990 - the boost gauge, water temp gauge, wiper control, etc. are affected.
On top of that mess, the CAS / ignition input wires are on the engine power harness on the 1987 Turbo II, but your 1990 NA runs on the engine main harness.
You'll need to somehow splice in the shielded, 4-wire bundle back to the 1987 Turbo II ECU.
If it's an "early" 1987 Turbo II don't forget the fuel injector resistor pack.
The 1990 NA doesn't have the two-stage fuel pump voltage set-up.


-Ted