just got in from the garage,

1. I isolated the master with plugs - rock hard pedal with engine running. Master cylinder and booster operating correctly.

2. blocked front brakes with a plug, had pressure to rears only. After bleeding rears, with engine on, good brake pedal. Rears OK

3. Reconnected front brake line to master, spongy pedal with engine running. Bled fronts, both calipers. Again spongy pedal with engine running. Rebled fronts, same spongy pedal.

All signs point to air in the front lines somewhere, can't find it. When bleeding calipers, get clear fuid - no bubbles. brand new brake hoses - rubber and stainless.

Did I possibly get a bad distribution block? can they trap air?

BTW: Cruzin, I got the prop valve from Mancini #WIL260-8419. I have the stock rear wheel cylinders.