Dave for what it's worth: I used a digital cliper to check the copper washer but this was after I tightened them in place. So, here is what I came up with .400 inside diameter, .627 outside diameter, .075 thickness. I tend to get very exacting (go overboard) with things. You (in my mind) can't over engineer.   

Man, folks were not kidding when they said this is one of the toughest jobs on a shark. I'm getting closer, but still not there yet. I replaced the M/C with a different one from Autozone, bench bled it and now I'm bench bleeding it again, because there were still bubbles coming out after it was on the car. And those cheesy plastic bleeder fittings that come with a M/C are apparently one time use only so now tomorrow I'll be buying another bleeding kit. I'm also going to put plugs in the outlets and test - the pushrod should be rock hard if it was done correctly.

Dave, I hate to tell you that the gravity bleeding is futile. Maybe it might work for you....I only hope for your sake that it works.

Hat's off to ya, Dave...I'm getting frustrated just READING this...and YOU'RE doing all the werk!

Anyway....here's what I would suggest at this point. You have to determine WHERE in the system the problem is. So...start with the master. Disconnect the lines, and verify you have fluid UNDER PRESSURE coming out of both fittings there. Not just fluid running, but fluid under pressure.
Then, connect the lines back up, and go to the next junction...the p-valve. Disconnect the lines to the front brakes, one at a time, and verify fluid under pressure. If you have good pressure coming out of the master, but not out of the p-valve, you'll need to replace the valve. Cross leakage inside of the p-valve will not cause the problem you have, so even if you left the seals off, you should still get pressure from both ends.
If you happen to get pressure on both the fittings coming out of the p-valve, then your problem HAS to be in the lines to the front calipers, either the hard lines, or the "new" flex lines. Make sure there is nothing restricting the flex lines....they can get crap in them from the factory, or by sitting on a shelf. If they get twisted, they can collapse, too, so just be sure they are free to flow.
From everything I have been reading, your rear brakes will bleed with pressure no problem, but the fronts are just dribbling. If the master is working, the only other possibility would have to be the p-valve, or a restricted line/hose.

When I say "under pressure", I don't necessarily mean under full pedal pressure...just enough to determine there IS pressure...the kind that might skwert ya in the eye, so be careful.

I would also seriously start thinkin about renting/loaning/buying/building a pressure bleeder....

Good Luck...hope ya get it figured out & fixed soon. I would have already beat the he!! out of it at this point... 

Thanks, Joel and Larry!  Yep, good advice about starting at the M/C and working down from there.  That's definitely my plan.  I almost think it has to be in the M/C or valve since I'm having problems with both fronts.  (and I know the single front hard line from M/C to valve is OK).  Unless there are problems in more than one line which I guess could happen.  A couple more questions: 1) when you say test under pressure, can I do that with a "thumb test" or do I need to rig up some kind of gauge?  2) Pressure bleeder: I've heard the $60 parts store versions have a hard time sealing to the old GM cast iron M/C's - any truth to that?  You're probably referring to the professional version, but I'm not sure I'll be able to find one of those in my usual list of "tool loaner" friends.  But I think I'm done with the sucky sucking (MityVAC) method - I think it's causing more problems than it's solving.  Thanks again - I'm pretty sure I'll nail this eventually.  All part of the fun! 

Sounds like you're having a nightmare with these brakes..can't say I haven't had my share of them myself..those brass washers ..seals usually don't come with hoses anymore..not sure why because they used to but a few years ago I noticed that they didn't come with them..I think the biggest problem is..if they are not included they should be a suggested part as they really only work once..maybe twice if you have to..don't feel bad about not putting them in..I can't count how many times I do stuff like that and knock myself up and down once I figure out what I did wrong..hopefully with the brass washers installed the brakes bleed out as easy as they can..one thing I do to help bleed is leave old hoses on the front and get the back done ready to bleed..then I pinch off the old hoses in the front with vice grips and bleed the back completely..then install new hoses on the front and it usually bleeds out pretty fast..I have done this a couple of times and haven't fought it as much as I did it without being pinched off...also...when I bled the front I jammed a small screw driver in between the pad and rotor of the rear on both sides..this keeps the rear pistons from moving..makes all the pressure go to the front instead of using some of it to go to the rear..this part was for when you pump the pedal to bleed..I may have done the same thing to the front at the same time but can't remember...the reason I did this was to increase the amount of fluid flow to the caliper that had the bleeder open...btw..I didn't use any type of power bleeder to do this even though I have you 2...I have used the old hose dipped in a milk jug tool immersed in brake fluid and just pump away..really works as it pushes out the air and sucks in fluid at the same time..really hope this helps as it did work for me.

Dave, put yer thumb/finger over the hole, and make sure there is enough pressure to blow some fluid out..a good stream, not just a dribble.

Don't know about the $60 bleeder sealing, but my $300+ one leaks a bit, too....that's what rags/paper towels are for...

Dave, this is what I used. It comes with J hooks (4) wing nuts (4) and 2 dinky chains. The best thing to create a good seal is to forget the J hooks and chain junk. Use two C clamps instead so that when you pump up the pressure it doesn't squirt from unsealed gasket areas. Here is the link:.............

http://www.summitracing.com/parts/MVP-0105/

The real prollem with the leakage from the pressure bleeders is folks thinking you need 30-40 psi to get the job done....truff is, 10psi is all ya need. I don't think I've ever pumped mine much over 15psi. Mine leaks mostly because the rubber gasket is old, has had brake fluid on it for 10 or more years, and it's just swelled, and mooshy. I really should get a replacement....one of these days...

x2 on  this trick. I use a 1/2" thick piece of flat steel that is 2" wide and 4" long on the bleeder cover and secure it with one C clamp in the middle over the divider wall in the casting. Pump up to 12-14 psi and start bleeding.

The copper washers will get hard over time, even unused new ones. If you anneal them they become soft again and will seal better. I put a piece of tubing or a welding rod in the vise, place the washers on the rod, heat until glowing and quench in a pan of cool water. It makes them soft and they seal easily when the bolt is torqued to spec.