I don't think any of the ferries have height restrictions that would pose a problem (after all, they do take trucks). They do like to know in advance what height your vehicle will be, as some of the decks will not accommodate high loads on cars, and that would affect loading arrangements.
Go to the ferry company's website and try out the booking procedure, and you will find that you are asked for the length and height category of the vehicle.
They might refuse a vehicle that looks unsafe, but I am sure that you will be careful enough to avoid that.