The 6.0l harness clamps on very hard. It's somewhat difficult to remove it once it's on. I found the bullet connectors I had as replacements to my stock harness just didn't work well at all. They were never tight enough to me.

That was someone else. A dump truck decided to not stop at a stop sign and hit me broadside on the highway. I have a 96 psd as my replacement. A good idi turbo was harder to find on short notice.

 

Chillman88, From above I wasn't able to tell if you had the newer 7.3 glow plug system and are thinking of switching over. I have heard that if the glow plug system seems behaves strange the controller can be gone? Most seem to like the 7.3 system. My 87 6.9 does have the newer system as stock. The drawback most have is with its location so they kick them off to the side.. especially if they've added a turbo which is something I intend to do. (adding turbo) I'm trying to work out all the small issues I have before adding a Turbo over top, hiding from sight and limiting access to the fuel / glow plug system. With the problems you are having I would also yank those injectors and clean them as I stated above. Its an easy task that has worked out great for me more than once.. saves the cost of new ones. If you can have them pop tested that might be a good idea. I didn't bother because anything is better than what I had (leaking injectors) After cleaning them did close nice and tight with an air pressure test. Washers adjust the pop pressure. Those who test them will say they are no good because the pop is off. Not true! The washers on top of spring change the amount of pressure as you've extended the length of the spring with another washer it takes more pressure to open... thus each injector, due to slight differences in spring resistance, has differing number of washers. So purchase a couple of used Injectors for the springs and washers and adjust your old ones with those parts to get the pop corrected. Or if you find the needle will not seat to cylinder opening try a different needle valve out of the spares you've purchased. I'm willing to bet even a 200k mile vehicle has salvageable injectors.