Hey there Rubberbubba, Im a chiropractic student and just thought Id offer my 2 cents. Though I am relatively new in the program, and have not yet had classes in physical diagnosis or clinical neurology, maybe what I am about to say can offer some info...
basically, there is a group of nerves called the brachial plexus which originate from your cervical (neck) region,enter the axilla (shoulder) region, and run down your arm and forearm. This brachial plexus supplies motor innervation to basically all of those muscles in your arm/forearm/shoudler region.If it wasnt for the brachial plexus, you wouldnt be able to curl 225 for reps and close grip bench 315 for reps, as I know you do.
Your arm falling asleep could be due to several things: you may be sleeping on your side, putting your bodyweight on your entire arm/forearm unknowingly when you sleep at night, and this causes compression on some of these nerves I described earlier, heck, it may even compress your axillary artery as well, hence your arm falls asleep.
Or, the problem could be higher up,meaning some of your cervical vertebrae are subluxated/misaligned/malpositioned whatever you want to call it, and so this malposition affects/compresses some of the nerves of the brachial plexus, and you feel the result in your arm/forearm down below (more downstream so to speak). Your pain/numbness can be charted out to different areas of your arm/forearm by dermatomes and myotomes, and this is how the chiropractor will know what vertebral level is affected. This is where chiropractic adjustments could be beneficial.
As far as sleeping is concerned, you want to sleep in a neutral position (on your back), with your head flexed no more than 30 degrees with a pillow. you can also try putting support (pillows) underneath your knees, but do not create more than30 degrees of flexion there as well. If you sleep on your side, make sure the pillow is underneath your head and ABOVE the shoulder, so that your nose is in line with your sternum. It is also reccomended you put a pillow between your knees when sleeping on your side as well.
Hope this helps