When i have a motor that is stuck i use CRC penetrating oil and it works every time.you need to fill up the cylinders and let it sit for a week and hit the starter ever once in a while It will brake loose.I had a 350 that sat for 25 years and was frozen solid and i got it running again CRC works man try it.P.S DO NOT PUT THE SPARK PLUGS IN IF YOU FILL THE CYLINDERS BECAUSE YOU COULD HYDRAULIC A ROD IF IT TURNS OVER!FLUID DOES NOT COMPRESS.Hope you get it un frozen.
