wanted info on aluminum case OD trans

im currently in the process of converting a 74 scamp automatic into a 4speed overdrive and am wondering if anyone knows the dimensions to the center of the shifter hole in the 4speed hump so that i can weld it in

drop the hump on the floor , it's pretty much will align itself where it needs to be by the way the weld flange is shaped and the contours on the floor .