Hi, I just read the above posts and I went out and measured the the level in my stock 49 1/2 ton. It was about 3 1/4" below the top of the rad filler neck, just below a deflector plate in the rad. It looks low but it is not. When I first got the truck I topped up the rad to about 1" below the neck and took it for a drive and it pushed out some antifreeze and then stabilized at that level. My truck runs at a steady 180deg. idle or at warp speed of 50mph, so if your truck will idle for 1/2 hour at a steady 185deg. the cooling should be ok.Let it cool down and check the level.
