They are two inches narrower and one inch shorter.
Ron, Don't have a foam mattress but we have a Mattress Company here in Peoria, IL that will custom buit a mattress to any size and hardness you would want, have used them at home for over 40 years. We have them make new one for us the day we got our 3100 home. We have the twins beds and they ran about $450 each. It will take up to 1 month to have it made. Hope this will help. Bad thing is they weigh a ton, not really but they are heavy.Jim
Yep, I measured them at 6" thick.