I guess I should have been more clear.
I got it all together with what I have.
However I did read the thread you linked and I did the same thing you did out back, ran the 8800 GVW calipers cause (my thoughts) bigger is better. Well as it would turn out the rear brake portion of most master cylinders cannot move enough fluid to the massive pistons. Initially I had my lines backwards and I was EASILY able to lock up the rears and nearly nothing up front (stock CUCV 1 ton GM calipers), I switched the lines to the proper brake circuits and can now lock up my 39.5x18-15 boggers (takes a heavy foot, but still thats a tough feat when tire only is 110 lbs!) at 35mph. Now I am still running the massive 8800 GVW GM D44 front calipers out back and I cannot lock up the rears but I can still feel them working.
I took the rig out last weekend and after a few hours I noticed my pedal felt a little different so I stomped on the brake pedal at about 30 mph and I locked up all 4. Now that was on DIRT and not asphalt, but I am thinking there may have been a small air bubble somewhere that may have worked its self out even tho I ran nearly a full quart of fluid through the rear circuit alone.
No matter they work better than they ever did and I was able to retain the factory brake booster on my 85 Toyota Land Cruiser. AND the master cylinder I chose had a "shallow" spot for the push rod which was pretty much perfect after the thickness of the adapter was added in. The factory master is much deeper than the GM one I used so I didnt have to make any extended rods or anything like that as I have seen people have to do before.
All in all I am pretty happy with it all. I may go back later and switch to the smaller calipers (the standard 76ish GM D44 6800 GVW front caliper) as it would require less fluid, and even tho it wouldnt have the same clamping power as the larger piston it would likely still work better since it would pressure up sooner.
A cool thing I noticed during this process is the pads between the two calipers will swap with one another and bolt holes are all the same. so if I went to smaller piston caliper I could still run the larger surface area brake pads.
Again, right now I am satisfied and dont really see myself messing with it and spending more money on something that is all basically brand new and working better than the factory disk / drum setup (even when properly adjusted) ever could even pretend to do. :grinpimp: