Well... the reservoir tank for the Cummins is aluminum, (previous engine had a steel one), but here's a pic:
View attachment 828572944
No pressure rating on the cap... but they usually run 16psi. No numbers on the part... so I'll have to pull the numbers off the engine... and on a free weekend go to the local Cummins dealer and see if they can find it.
Once that's done and the sight glass is acquired... It's a matter of figuring out the size and threads... then ordering a bung from the website link in a previous post.
Of course this may depend on whether or not the Ebay degas holds the same liquid volume as the OEM plastic one.
Any ideas on that Stinking Lincoln 1 ???