I have these 149 from when I was on 8.38/8.5. They've got life left, got a fairly new set of 139 as well, however, I don't see myself going above 8.25. Wasn't sure how much I'd notice 139 vs 144 or 144 vs 149 to warrant coping some.
Put the 149s on with NO washers on the inside (two on the outside) more so just to feel where the wheels sit, because that is almost the same as with two washers on the inside of 144s.
In the same way, put three washers on the inside of the 139s and compare where your wheels sit in relation to the 149s with no washers. On my setups, they are almost the same.
As much as the truck axle ends sit at 8.5 on 149s, usually unless you have three washers on the inside and or fat wide wheels, your truck and wheel setup is never going to be that wide, which is why people had successfully run 149s on 8.25s for a long time before 144s came in.
* Sometimes trucks will not fit three washers, but if you don't run spacers in your wheels, they fit with room to spare on most wheels I have done this with.