You mean 4x5 feet, that would be about 120x150cm right. Metric system over here.
I problem with making a drum and put the paper inside is that when the paper gets wet and soaks up liquid it gets heavy and collapses into iself.
Besides the drums would be gigantic and you would need to build a new house for them.
I have made numerous prints ranging up to the size of about 140x280cm, being about 4,7x9 feet.
I developed them in long drays about 150x50x20cm large and rolled the print. There is also a rolling device made by Deville to develope such large pictures.