Only thing that I have a hard time trying to figure out is when the next one is going to break.

 

Sorry Chris but I myself work in the shop not in the office. You need to leave a message for me to call you back. What year is you 80? If you are going this route with AN fittings and are using a center lube unit (97^) you will need to modify the rear fitting to make it work properly for the later unit. Maybe you should call and leave me a message!

 

I'm just giving you a hard time. 1Slow01Z71 actually mailed me a stock one that he wasn't using. I'm good to go.

 

Take apart my core, i wanna know what i fryed

 

The have the same threads per inch as 1/4" NPT, but they're not tapered. You have two choices with this:
- Thread in the NPT adapters carefully and not too tight with semi-hardening thread sealant. Do not crank them in, you can actually crack the trans.
- Or, run a pipe tap into the trans and get some taper to them. Obviously this would only be advisable if the trans is apart so you can clean it, and of course you can't go back to stock. It would be solid and leak-proof though.

The rear fitting on a 4L80-E that Vince mentioned is the return that must protrude through the outer case and through the seal in the center support to lubricate all those parts. If that special fitting isn't used the geartrain, main shaft, and sun shaft will eat themselves up.

Here's a photo that sort of shows the difference in threads.