Before '99, everybody used the V-601P, (-PU, -PD, ...).
I heard rumors, that the 5P73 could handle only 3pcs of V-601D, as those weight is higher.
As far as I can tell, the V-601PD is the 5V27D.
Those rumors are familiar to me as well, but it appears that no such restriction was in place with the latest S-125 variant.
For example:
And, is it known if Serbs used this missile against F-117 or the older type?
I believe that they did.