Some "Tender" Opinions, Please...

Agreed. Original tender BIG. Go with Modification of 1666

I prefer the original, i.e. big, tender, since it holds more water for branch line freight or mixed train service.

That is not a big tender. THIS is a big tender:

https://www.flickr.com/photos/gmpullman/47957120288/

Especially in late steam days when coaling and watering facilities were being closed, big tenders were needed. Many a loco gave up its smaller original tender for a larger one that had belonged to a larger engine that was scrapped. Auxiliary water cars were also used to extend range. If you are modeling the steam to diesel transition period, your existing tender might be the best fit.

Depending on your curvature, I might try to shorten the gap between engine and tender. You could also consider adding a deck plate between the two--.010 styrene, perhaps.

Personally, I think the 1666 tender with its giant coal space looks like it belongs behind an NYC Niagara or something. It definitely says "NYC" to me, and doesn't fit that UP loco. Not to mention you are converting your oil burning UP to coal.

But, hey, it's a hobby. Do what YOU like.

Since you asked for opinions, I think a Vanderbilt tender looks "right" with a UP steam locomotive built before the late 1930's.

Mark,

I like the 2466T tender, but keep in mind that the same locomotive could have different tenders.  The Pennsy equipped their I-1s Decapods with both short and longer tenders.

In the end, it's what you think that counts.

George

I checked my 1952 CNW LOCOMOTIVES book after seeing your question.  Class Z 2-8-0's had a 30 foot tender that carried around 10,000 gallons of water and 15 tons of coal, more or less. Might be helpful in determining which tender to use.

Mark,

   I like the look of the 2466T.  But at the end of the day, it's your railroad.