I have found that the mattress in a 670 is 35x79. I don't remember how the bed enclosure is constructed. Can you get a standard twin size mattress in there? Standard twin measures 38x75. Thanks for your help, Toby
well you have a 35 wide, and you wanna stuff a 38...HHHMMMMmmmmmmmm i have always found the bed slab to cut it very close to the mattress size...good luck