One factor that hasn't been discussed much here is the weight of the car. For general street driving I prefer a lower stall speed on a heavier car; otherwise, the converter spends too much time slipping up toward stall speed to motivate the beast - this is called "looseness." For racing, the opposite proves true.

Given the two options, I'd be inclined to go with FTI's recommendation for the above reason. As for Yank, whatever FTI's advantages, there must be some reason why the Yank SS3600 is the most popular converter on this forum

 

Until this swap I couldn’t tell you what a Yank, FTI, Circle D, Precision, TCI or any other brand torque converter was. The learning curve has been great the past few weeks. All brands that I spoke with factored in the 4500 pounds of my car. The tighter stall converter would be looser because of this. It takes a lot to get the old Buick going!