Beef Tallow.
After 4 ish hrs, and the right feel in hand, the cheeks go in there, get sealed up, and do another 3 ish, or until they have the correct tenderness.
I sometimes order from an online butcher. Many have them, but I get mine from Porter Road usually.
I also get them from my...
1.7g heavier, would, at speed, effect the way the shaft loads/unloads, and could def be a factor in the extra speed.
I'm not going to do the math, but 1.7g becomes much more at those speeds.