When BHJ made theirs, the had the 261 bore on one side and the 235 bore on the other.
if you make them, let me know the cost - I sure wouel be interested
The reason they are used, I am told, is that when the head is torqued, it actually can bend or deform the cylinders due to the forces of the headbolts. I dont know if it is theory or practice, but that is what I am told
