Tri-Y Headers for torque?
There are many theories about what works with various combinations.
Pete McNicholl who was a member of the Ramchargers was successful with tuning the exhaust system.
Here is his dragster from the early sixties.
The collectors are way down the head pipes.
His Willys had a form of Tri-Y that he made.
I have these that were made years ago, back yard Tri-Y.