i am remodeling a bathroom, first one, and the toilet is located 14" from wall and i want to relocate it to 12". the piping is all cast iron and am wondering if i can just cut pipe and use a coupling and use pvc form there to the toilet flange. the stack is located directly behind the wall behind the toilet. also the drain from the tub is located on the same horizontal run as the toilet. is it ok to have this setup or is it not code any more. the house is 90 plus years old. also how do you separate a cast iron joint?