I put a different piston in the oil pump to double the oil output. It tends to make a mess, but I like it like that - I know the bar is getting lots of lube.
As far as chain stretch, the NK chain has the same bearing surface (drive link cross section) as standard .325, so chain wear isn't a problem, but there is less contact surface on the bar to distribute the load so the bar wears faster because there is greater lbs/inch on the heel of the cutter. For saws over 60cc I wouldn't suggest it for commercial work, but for a 68 year old firewood hack like me, the ugly POS can go longer than I can.
For a 372 you would need a 'small mount' configuration to get the NK bar on. I had to do a fair bit of tweaking to get the NK Husky bar on a Stihl mount. Not a big deal once I figured it out the details (new oil groove, redrill the bar, different tensioner), but a crazy swap like this is something you have to work through before you jump into it.
Oh, I also found that I needed a set of double spikes to help keep the cut straight during a bucking cut. It cut so fast, and with the more flexible bar, I found that I was weaving all over the place. Now I can pivot on the double spikes to keep the cut straight - it made the saw much more useable for bucking cuts. If you put a NK bar on a 372, I would expect that you would need the double spikes.
