340 sb 1972 - external balance

Hi Guys,

yesterday i visited my brother who´s working on his 69 dart, Engine is out at the moment. The car came originally with a 273, now has got a 340 from 1972 with a cast crankshaft, external balanced (weighted balancer in front). The Trans and converter is still the one used with the 273 - is this balanced correct? Do the external balanced cast crank 340´s use a weighted flexplate / converter? There was no vibration or sth., just want to be sure.

regards

Michael