8" vs. 9" convertor

The larger the converter body is, the looser/sloppier it needs to be to achieve a certain stall speed. A bad converter shop can make a 11" converter stall 4300, but it would be complete garbage compared to a nine inch 4300. (I know, I had one. The single worst hotrod part I have EVER bought.)
Given the choice of a tight eight inch for 5000 stall, or a nine inch for the same stall...... I will take the eight inch 100% of the time! (My last converter swap picked up two tenths in the eighth,from low 10s to high nines 1/4)
Edit: if GTX John says buy an eight inch, buy an eight inch!!!