[PRR-talk] Erie-builts w/steam generators?

[Frederick Ripley]

Folks,

Am I remembering correctly that a couple of sets of Erie-builts were  
delivered to the PRR w/steam generators, and listed as dual service,  
at least until about '54
when the various regearing was done?

If that's right, what were the nos. of those sets?  Was the class  
FP-20, rather than FF-20?  Has anyone seen shots of them in pass.  
service?

Thanks, Fred R.