Are you sure the support is "backwards"? It would be difficult to get the inner aprons, hood latch and grille to fit if so. I recently installed a 61 235 in my 51 Burb. Changed the water neck and slid the water pump collar back on the shaft and cut off the snout. I was able to go with the bigger fan blades. I'm courious what your refering to by "cut up" upper/lower cowls? Got some pic's? The tech tips has good information regarding the engine swap.