disc/drum to ls1 disc/disc
 

Everything else I have except correct combination valve.
What do you think about my options:
1. Modify the stock combination valve into a adjustable unit. Has anyone done this or even thought about it? Is it even possible?
2. Modifying the stock unit to match 1le specs. All i need to know is what are the differences between these two. I guess that the spring in front of the combo valve is all what needs to be changed. The question is only what spring rate it has to be?
3. Using the stock combination valve and installing wilwood adjustable unit in the rear brake line. What I have read on these boards is that the stock disc/drum valve gives too much pressure to the rears. Based on that I think that this would work.

I want to keep the stock unit for stock appereance. I can not just go to a parts store and buy a 1le unit, because in our local parts stores they only have parts for european and japanese cars (this is in finland) and IF i ordered 1le combo valve from USA it would take several months (can't take that risk, summer is coming, snow is melting and I want to drive).
The "bolt mod" for stock combo valve is out of question, because it is only replacing one problem with another

Hope you can understand my poor english