2500 is fine if it's a good converter like a Hughes. In the old days almost all high stall converters slipped bad so 2000 was about as big as you'd want to go on the street. Nowadays they've figured out how to make converters flash stall very high rpm and not slip much. My previous converter was a PTC and built to stall 3000 behind my engine and before I installed it I was running a MP converter that stalled 2200. When I installed the PTC I could barely tell any difference in the way it drove from the MP 2200 but when I layed into it it'd stall 3000-3100 and made a big difference on how quick my car was.
