As I understand it, a higher number of smaller holes will give more pack. The oil can only pass through a small hole so fast under compression. I would say that the 1.1x10 hole piston will give the most pack, and the 1.4x8 hole piston the least.

I'm still doing testing, but I think there are better options than the stock pistons. The stockers have too much pack, and make the truck too reactive and twitchy. I put in Kyosho 6 hole pistons drilled to 1.4mm holes, losi 35 wt oil from and rear, stock springs, and tested it yesterday after racing was over. (didn't race it, prefer 2wd buggy indoors). Practiced with it there last week as well, and had the local setup guru drive it as well. Truck was good last week, but kinda twitchy and assy under power out of the turns. He recommended camber link changes and to try different pistons, to give the truck a more plush ride and improved stability. Made the changes and the truck was WAY better, even on a drier track. Very predictable when getting hard on the power around and out of the turns. Still needs a bit more tuning, the front end dove hard landing off some drop-off style jumps, and the rear oil, to me, felt a bit too heavy. Changed to losi 30wt oil in the rear, stood the rear shocks up one hole from all the way inboard on the top, and went to Kyosho orange front springs. On the bench, the front and rear suspension feel more balanced now, and both rebound the same.

I think the stock pistons are better suited to a heavier vehicle, like the 1/8th scale. I think 6 or 8 hole pistons will work better in this truck. IMO