From Roll Pan back to Bumper

[BugzC10]

I'm going to convert my front end back to having a bumper. I'm going to put back what the PO hacked off the frame, but I need a measurement. I have the complete schematic of the frame measurements, but it is nearly impossible to get an accurate messurement with the truck assembled and attemping to do it by myself. What I need is the measurement from the leading edge of the radiator support bracket to the end of the frame horn. This way I can tell how much of the horn I'm missing or need to replace. I'm going to post another tread in the for sale section to buy a set of horns that I can then cut and attach to the end of my frame.
Thanks in advance for your help.