Just a question for you, The thing lives has a very strong cover, so If you will drill this ball with the strongest drill of stacked 3 3/8 x 3 3/8, do you think you can handle it?
For me, I would drill that 4 x 4 or even 4 1/4 - 4 1/2 just to be on the safe side that will be more playable on whatever surface the ball has, sanded or polished(adjust on speed) 'coz on a house condition, it is very strong for me when it is sanded, but if it is polished it's more tamer.This ball has a very strong midlane roll that's why it is meant for heavy oil.With a very strong drill, there's a possibility of a burn out.
As luckylefty always say, drill your strong balls "weak" & your weak balls "strong"...
Just my opinion...
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Thanks,
Triple X