What brands/ product lines of HO F Units are 15" radius curve friendly (i.e., they can negotiate a 15" radius curve without modification)?

Preferably you've tested your own locos so you know they will work.

Appreciate the insight.

 I'm interested to find out if any railroads had or tested/experimented with single truck (presumably 3 axle) slugs. I have an obsession with B units, slugs, fuel tenders, etc. and the thought occurred to me last night that that might be the answer to a short line or yard that needed a little more oomph for some jobs. Just a question with maybe no answer.  Kodachrome  John   P.S. never posted a new topic before (does it show?) so any corrections needed by Mr. Fugate may be done as necessary. 

I recently purchased a Proto 2000 2-8-8-2 off of eBay. It has some issues with broken and missing parts in the running gear. Does anyone know of a source for parts outside of Walthers? I contacted Walthers and while they do have parts, not the parts that I need.

Well, I'm at it again. My light build and 250T darrick is on hold waiting on parts, so on to the next. 

I bought 3 Athearn Alco PA-1 locomotives and 2 PA B units so I can make a A-B-B-A with a reserve A unit. All are powered. 

I started the project by disassembling all the parts and starting on the frames. I deburred the frame castings, rounded off edges and sand blasted with F100. I did the same with the trucks and each wheel - without hitting spindles.