Sparkplug tightening?

I always do 'em finger tight, plus 90 degrees.

I think they are a tad under as I did notice a slight increase in engine sound (meaty roar) when under load and the engine hot so maybe some combustion leaking through. I'll give them a 1/4 turn tweak.

Rule of thumb is about 12ft/lb torque so "just nipped up" which is about what Steve would be doing.

But it's different whether you're using new or old plugs. Maybe he always means new ones. I do them until I can fell the resistance change and tend not to hang off the end of a breaker bar or anything. Buy a torque wrench if you're concerned.

Since fitting the Bosch plugs I today noticed a slight misfire just as you start to accelerate under heavy engine load. I have experienced this before and it turned out to be a HT lead breaking down but these are new. In the end I decided to ditch the Bosch plugs and bought a set of NGK V grooves the same as were previously fitted. Boy what a difference, for starters when tightening the NGK's you get a much better feel when the washers are compressing and can feel the springiness. A good half turn and it felt just right without much effort. With the Bosch I was using more force to tighten them just a few degrees past finger tight. Gave it a good test run under various engine loads and couldn't replicate the misfire and seems a lot more responsive. It's NGK for me from now on.