I’ve seen several threads on this subject but no one ever came up with a “GM” part number, just the AC Delco number of GT250 which is correct for our Diesels.

I finally got around ordering one from my dealer. He could not find anything “listed” under my VIN for a locking cap.

So he crossed the AC Delco number and came up with GM# 15070014. It has no loop but after placing the old cap and tether in a bowl of boiling hot water for a couple minutes, it came right off and slipped on to the new cap with ease.

Hope this helps to those who are trying to protect their tanks full of liquid gold.

Nice find. :)

I think I'll be picking up one of those this weekend.

A search probably would have saved you leg work.;) http://dieselplace.com/forum/showthread.php?t=9364&highlight=gt250

HD-Nate,

After taking your post to the stealer today I asked them to check for the part #. They told me there was no locking cap for our trucks. I begged them to check. After about 10 minutes she came back and said "I guess it will work, huh". They ordered it and I can pick it up Tuesday. Cost is about $16.

Thanks again!