One advice i`ve also heard was to keep the rod ratio over 1.75 Gen1 busa it`s 1.89 ,gen2 1.83 and +9(72mm) with stock rods 1.66 , so it`s easily going down.
Fred, do you have stock length rods ? If so, it`s 1.63 for you.
I had +8.5mm stroker with +4mm rods, ratio 1.72 , it was gaining hp until 11400 and limit was 11600.