Being bored (-namely it's too breezy outside to be fun to work on the van...) I did a bit of research on some of the other EGR Delay Timers, and I found that they are becoming much less common! Take note of this if you need one: AC Delco has *completely discontinued* them, (I called to verify this) and Standard Motor Parts only still produces their EGT3. (I called them too!) It looks like KEM has discontinued several of them as well!!
Working on antique vehicles makes me feel old sometimes...
Since I have two timers on hand I decided to see what their delay times were. My various manuals claimed the idea with the EGR Delay Timer & CTS system is to prevent the EGR system from operating until the air charge (air fuel mixutre) temperature reaches 60 degrees, and to delay an additional 60 seconds after the air charge temperature does exceed 60 degrees. (In cold weather they figure on the air cleaner's Heated Inlet Air System to eventually stabilize the air charge temperature at around 100 degrees once the engine's exhaust manifold has warmed up sufficiently.)
I set up a bench power supply and wiring to simulate the CTS and EGR solenoid, and found that my Mopar 4111181 is a 90 second timer. This is equivalent to a Mopar 4111481, and the SMP EGT3 and KEM 173-603. These are the Red or Gray colored units.
My Mopar 4111180 is a 60 second delay unit. It is orange colored. These appear to no longer be in aftermarket production. The good news is that the connector and wiring is identical to the 90 second units, so a 90 second delay timer could be used as a drop-in replacement - giving you a slight additional delay before the EGR kicks in.
I don't have one of the 4111179 timers (black colored) to test, so I don't know it's delay time yet. If I find one I'll post the results.
As a further public service, I'll add the only diagram I've *ever* found for the correct and complete Emission wiring of my van - a 1981 Dodge Ram B250 Custom Sportsman 6400 GVW maxi van with 318 & 2bbl carb. It also applies to the 4 bbl version, and the 360 4bbl. The Haynes and Chiltons diagrams aren't even close, and even adjacent year Dodge service manuals don't have this exact diagram.
Oh, BTW - I found it is necessary to test these EGR Delay Timers with a load which approximates the EGR solenoid resistance. I used a 30 ohm resistor. Without the load they won't toggle their output.