I'm in the process of getting a spitfire girder made. I want it to match a 4 under DNA springer. I just wanted to make sure the measurement I gave him is right. 22 inches from bottom of neck to center of axle. I'm thinking of running a wm2 21 inch repop wheel how big will the opening between the forks need to be? I also don't know how long the stem will need to be. It will be going on a 55 triumph T110 frame.