At about 70kph under very light throttle, then getting back on the gas but still only mildly, my engine feels like it hiccups before it gets going. I doubt it's leads, that’s normally a load issue right? So maybe wrong temp plugs?

Also I’m only getting 10.5 to 100kph (offhand stopwatch). I’m going to borrow a g-meter and run before and after tests when I change the leads (originals at 150k) and plugs soon - just to see what happens.