Funny part with that, is he actually cut down and drilled out the stock hammer on the bighorn to get the power increase he achieved. Cutting it down from the rear does me no good, since the sear engages the hammer in the same spot no matter what. The only way I see I can get more dwell is shaving down the rear of the valve and adding length to the front of the hammer.
This is how the jumbo hammer looks, the mega/np03 hammer is what I have which weighs less but has a larger spring cup for bigger springs. 12 mm for np02 vs 8mm on the jumbo.
View attachment 449166 The front section stops at that lip and engages the sear on that edge. The section that is turned down does into the valve cavity of the block and hits the stem.
If I add to that section and shave the valve to let more stem protrude, it would open the poppet more.