I bought Intermountain 28" wheel sets for my Athearn Impack cars but haven't had time yet to install them.
Rio Grande. The Action Road - Focus 1977-1983
ATSFGuyAthearn Bluebox Impack Cars
Been a long time since I owned and operated Athearn Impack cars, but I recall installing JB wheelsets without incidence.
Regards, Peter
Exact Rail (www.exactrail.com) has 28 inch all metal wheelsets in HO scale, including code 88. I don't own any Impacks therefore, I can't speak to the issue of axle lengths.
Here is a working link:
https://cs.trains.com/mrr/f/88/t/69065.aspx
Warning, as maxman mentioned, the thread contains an absolute horror story about trains hitting the concrete!
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
https://cs.trains.com/mrr/f/88/t/69065.aspx (you'll have to type this in; won't link from here.)
The post above indicates that they are 28 inch. You'll have to scroll down in the link to get past the part where the neighbor's kids dumped a 35 car train of them onto the floor and everything was smashed.
I'm about to get another set of Athearn Bluebox Impack Cars to add to my fleet. what metal wheelsets should I use to replace the plastic ones?