no its not against the rules in any way . its also nto against the rules to SELL or MAKE a head that resemble other peoples styles / heads after all u made it so it dont count as plagerisim
REQUEST RELATED RULES:
7. Do NOT request a texture replicating or even BASED ON someone else's existing texture. It doesn’t matter if they're not wearing it or if it's in their store, if you want the texture, you'll have to buy it from them. Trying to get a texture made that is similar to or the same as an existing texture really, really pisses people off. So DON'T. This includes asking for “A texture set in the style of [Another User]”. Do your best to describe what you want without relating it to someone else’s work.