At 160 degrees I'd want trans fluid to just be maybe 1/16" above the bottom hot fill line, absolutely no more than 1/2 way, because if it's full to the top at 160, it will probably blow fluid out the vent when you tow something really heavy in 100 degree weather in stop & go traffic. Although I have never blown any fluid out on an Allison, I did out of an older 480LE. Sure messes up the underside of your truck.
02 2500HD LT D/A SB CC 4X4 BLACK, Westin stainless nerf bars, BW GN Hitch,Racor 60S post oem fuel filter, Oil Guard bypass engine oil Filter. All synthetic fluids. Kennedy boost valve, edge, Modified air intake,EGT & Boost digital gauge,TransferFlow combo fuel & tool box, Air Lift Suspesion Bags Rear & compressor with remote, Bilsteins front & rear, Frontier front replacement bumper.