It may be difficult but, each rooster can handle 10 hens. They will probably fight over them once their hormones start raging. They will be overbreeding your girls badly, and damaging or even killing them. You'd need 38 more hens to keep things at an even keel and probably have to separate them into 4 flocks, so the boys don't battle each other for them. That's a lot more hens, unless you just keep the friendliest roo in the bunch and add another 8 girls.