12 or 4 weight crank?

[dwg86]

I’m gathering parts for my next stoker for whenever, or if ever my 4.0 dies (327,000 miles and still going strong). I bought a 12 weight crank years ago and it’s been sitting in my basement. I know some claim the 12 weight cranks as being stronger and able to handle more vibration or dampen out vibration because of the 12 counter weights. But is the 12 weight crank necessary for an engine that will rarely see rpm’s above 5k? Is trying to turn an extra 20 lbs of crank weight worth it? I was just wondering about this since my current 4.0 with its light weight crank has lasted 327,000 miles and still doesn’t leak or burn oil (well I have changed the valve cover gasket and rear main seal).

[Cheromaniac]

For normal driving either crank will do fine.
The 12cwt crank has a slight advantage when offroading since its extra inertia reduces the risk of stalling the engine, while the 4cwt crank is better for racing since it allows the engine to rev up faster.