Yeah, that was my discovery too, the breaker bar being in the way.
Perhaps it’s simply a two man job? The only way I could figure to do the job was to thread the belt on the top pulleys and then have a friend pull the tensioner back while I threaded the bottom.
I denied myself the “proper” tool for Serp Belts for years…till I simply couldn’t do the task on a certain vehicle without one. So, I went n bought one…and have used it ever since… Its a long flat piece of steel with a switchable square drive end… Switch between 3/8 and 1/2…the long thin nature of the handle sometimes makes all the difference. The length helps with the leverage needed and the thinness of the handle…also comes in handy. They aren’t expensive and even HF Tools carries a clone of a real one…if you do more than 5 Belts a month its a no Brainer…
Blackbird
Had one. The weld broke. But the breaker bar works fine.
Neither tool solves my dilemma.