Eko Lower Chamber Refractory Replacement?

I used the new blocks a couple years ago. First off I had to grind them down slightly to get them to fit in the lower chamber.
They worked fine and it was a bit easier to clean the ashes out,but after one season(10 full cords) they were pretty much shot.
I don't think the cement mix was as good as the originals.
Now I just use regular fire brick with 4 or 5 laying flat and a few on edge to form a bowl.
They do eventually break but the cracked ones I use on the bottom.

I replaced the lower refrac. blocks with fire bricks been working great for a couple seasons now. I did a mix of thick and thin fire bricks to make the bottom and then a few on edge for the sides. Cheap and easy!

After better than two years on the shelf, I am now using the new style secondary refractory in the Eko 25. The originals broke into too many sections and it became a hassle to R&R for cleaning. I gotta say, so far so GREAT!

The original refractory worked well enough with additional firebrick for damming. With the new style refractory, firebricks work well for directing the blue flame and taking abuse. Firebricks are an easy and economical maintenance item. My procedure is as follows:

1. Place two firebricks stacked on edge horizontally and slide to the rear until 1-1/2" from the bulkhead
2. Slide two tunnel pieces to butt against the two stacked firebricks, and then ad the other two butting to the first pair
3. Lay two firebrick splits on the floor of the tunnel to absorb the abuse of the blue jet wash, one is cut short to fit
4. Place two more firebricks stacked on edge horizontally 1-1/2" from the refractory pieces to absorb the abuse of the blue jet wash thus saving the door refractory

The path of the blue flame comes straight down and can only go towards the door end of the chamber, it then hits the two firebricks and squirts to the left and right hitting the sidewalls of the water jacket and heading towards the exchanger tubes. So far am very satisfied with the new setup. After dialing down the fan speed it will not blast the sidewalls, but by then, the refractory and firebricks are glowing. Hopefully these new pieces will be more durable and far outlast the firebricks.