Just had to replace the tank on my 72 CB350. I ended up getting a CL tank for a great price. I love the look of the CL tank, but the CB seat is too short now. I'd like to fix the gap between the tank and the seat, but am very new to riding and mechanics. If I order a CL seat, is it easy to swap out a CB seat for a CL seat so it'll fit the tank? Do I need to order a new seat pan? I'm a newbie... help!!