Hi Everyone, I have a question I am hoping someone can shed some light on. I recently replaced the engine in my '06 Envoy. The repair manual said to mark the position of the Torque converter to flexplate position and reinstall it in the same position. I'm assuming due to the way it is balanced? Well my questions are, what does one do if they install a new torque converter to ensure proper balance? I replaced the engine with a used engine that had the flexplate attached and my partner convinced me to leave the flexplate on the replacement engine and install it, while I should have listened to myself and swapped them and installed it with the marks lined up because I swear I feel a slight vibration when the trans is in drive now. It bothers the heck out of me that I allowed myself to be talked out of doing what I knew to be the right thing to do just because the person I was working with just wanted it to be done. Now I have to deal with a lifetime of vibration and any problems that may come from it over time. So what happens when one installs a new converter? Is there some procedure for balancing it to the flexplate/engine? If not, how is proper balance then achieved and why did the stock one need to be replaced in the same position? Or does one need to buy a flexplate/ converter as a matched pair in order for them to be in balanced or take the flexplate off and have the two balanced to one another outside of the vehicle? I've never heard of that procedure, but what the heck do I know? Not much obviously. Sorry, I do not know much about how it all works. Any enlightenment would be greatly appreciated. Thank You