Thank you everyone for your help
It took about 20 minutes per each back cylinder to bleed-but there done.
they work great!
If it really took that long to get fluid to the rears, I'd suspect a partial blockage in the rear flex hose; how old is the hose? (it's dated) When flex hoses age, they deteriorate and swell up/delaminate on the inside (not visible from the outside), forming a restriction to normal fluid flow, and worse, they become a check valve that prevents fluid flow back toward the master cylinder when you take your foot off the brake - that can cause the rear brakes to drag, frying the linings.