Hi Guys .. yesterday tried first time my new 572 .. but some problem with or without nitrous ... at Launch engine go up down... up down ... RPM ! look like bad converter stall ... any idea ?

1970 Cuda 496 street driven 9.22@150
1971 Demon 572 7.82@176
1957 Desoto Adventurer Convertible 345 Hemi
1958 Plymouth Fury Christine
2008 Dodge Ram 1500 Hemi
1970 Dodge ChallengerRT 6pack 4 speed 1 of 135
1968 Dodge Charger RT 4 speed