Radiator cap- Oh, oh

[Chris & Ranae Procyk <procyk19@domain.elided>]

I just bought two new radiator caps for the WM and the T'llete.  Stant showed the same number, I swear.

BUT... the T'llete has no ovf tank, and the WM does.  So one of them has a problem- hopefully the "safe" problem, that is, the open air one.  How do I tell which is which?

**In Use**
'70 1200D 4x4 Travelette 392 4spd
'73 1210 Wagonmaster, 392 auto
**Prepping for Repaint**
'67 1000B step-side p/up  BG241 + 4spd
**Parts (future projects?)**
'71 1010 Travelall  392 auto
'67 1000B Travelall 266 3spd
'68 1000C 4X4 Travelall 345 auto