The 59k engine in my 87 na is blown from water seal faliure. I was planning on swapping in a s4 TII engine and using the turbo wiring harness and ecu, but If im going to use the ecu/wiring harness from the turbo then why not just get a s5 engine instead? I wont have to swap the oil metering system or water pump will I? I can get the s5 engine for the same price as the s4. Will It be any harder to do the swap if i use the ecu/ wiring harness from the s5 engine? Thanks in advance.
Chris

 

If you go with the S4 engine, ECU and wiring harness, the only problem you should have is there will be no plug for your alternator (the one in the back of it).

If you go S5 engine, ECU and wiring harness, then you will have to change the wiring harness behind your dash because the plugs will not match up with the ECU.

If you go S5 engine with S4 ECU and wiring harness, then you will have to go with S4 components on the engine (MOP, TB, inj, etc)

Dan