I was going to use the 895E's in the rear when I bought my suspension since I was looking for only 1 1/2" lift in the back. I did'nt buy them but was told on the other forums that the OME's at 260 lbs would be very very firm for a stock truck with no weight in the back .
I went with SAW's and they gave about 1 1/2" in the rear and are plenty stiff at 213lb. I read somewhere that the stock rear springs on the 5ths are 180lbs ,not 150 but I can't find it now.
Here's an outdated chart on some rear spring rates .It's even before the 895e'S were out but it gives a general idea..... I think Downey and Deaver are out of business too.
Rear Spring Comparison - Toyota FJ Cruiser Forum
The good thing about it is... rear springs are so easy to change out and they do hold their value. So if they don't work for ya ....just swap them out and sell them .