may wanna provide what brand converter as converter stall ratings are not rated the same. for example my 3200 pats converter will only give me 2800 engine stall @ zero boost. after calling pats I was informed that they rate their converters for approximately 3-5# boost. after checking I found my cars rpms to be 3150 at 4#'s.
I think PTC converters are rated at zero boost.
Just trying to save you the time of having to change converters, good luck.