Even when you use 5 springs... you can still adjust the spring tension by screwing the trem claw farther away from the trem block... this stretches the string and uses more tension from the springs... I use GHS Zakk Wylde Boomers (.10-.60) or something like that. Not positive about the E string gauge. But I have these installed on my number 1 Strat with all five springs... I don't use my trem hardly at all... if ever... So I went ahead and "screwed the trem down". I basically cranked on the trem claw screws until my bridge was flat against the body like I like it.

I'm not too familiar with the Kahler bridges... But like I said... it's all about adjustments. There is more than one way to adjust bridge tension besides just adding or taking off springs...

They make gadgets that help as well... like adjustable trem setters and hipshot trem springs...