Battery box location measurements needed

My 69S project had been previously clipped for the mid eighties 930 treatment. :( In an effort to restore it to more original spec, I am rebuilding all the front end sheet metal.

I have stripped and converted G-body inner fender panels but now I need to install battery boxes. The problem is that it is a clean slate and any and all reference marks are gone so I need some help determining their correct location. I have them mocked up and I think I am close but something tells me they need to be a little higher.

Any thoughts on how to determine the correct location? All my other cars are out at different shops so I can't pull a measurement off any of those.

http://i172.photobucket.com/albums/w...psejmwszoo.jpg