Before serial production of stroker flywheels got started, the early drag racing and hill climber heroes sometimes ran UL flywheels in their 61" & 74" OHVs’ for more cubic inches and higher compression. The stock 61" OHV stroke = 3.1/2", 74” OHV stroke = 3.31/32” and the stock 74" & 80" UL/ULH stroke = 4.9/32”, so the UL’s quite a bit longer.
At times when even this new longer stroke wasn’t enough, the crankpin holes were re-drilled to fit FL pins (=1.250”)* and the crankpin was mounted offset, so the stroke now became a massive 4.13/32” sometimes two right-side flywheels were used to get a lighter and quicker revving flywheel. The very forefather of todays stroker flywheels; Liberace's feet.
Modern Truett & Osborne 4.1/2" stroker flywheels (lightened) Liberace's feet!
It’s the combination of all these little tricks put together that makes the magic happen. I’ve dreamt of running a dual right-side offset-drilled UL flywheel setup ever since the first day I heard of how they did it. And now, I finally will. These flywheels are like Liberace’s feet, and without his feet there would be no music.
*I googled the diameter of the FL crankpin to seem cooler than I really am.