Adjusting proportioning valve?

[WSSix]

Is there a proper method for adjusting the proportioning valve or is it really just a matter of feel and or preference? So far with what little I have driven the car and done brake checks, I like the way it stops. I really have nothing to compare it to though. My factory 79 brakes were crap and a C5/6 is much lighter than my car. Really, I'm just slamming on the brakes and going whoa that felt good, lol.

The car has C5/6 front brakes and C5 rears. The front system is from Tobin at Kore3. I'm using my factory 4th gen master cylinder and factory 79 booster.

I have only really laid into it a couple times but have not locked up the tires at all. I have Sumitomo HTRZ tires. I have no idea if I should be able to lock up the tires. I would think so though. I'm simply using that as a metric for braking power even though locking up is not a good thing.

I do have access to a infrared thermometer if that would help. Any advice is appreciated.

Thanks