Peter,
Not to make you question your radiator install, but if you're having clearance issues, have you thought about installing at an angle? I put mine in at somewhere around 60 degrees and managed to get the cap under the radiator fill opening in the nose
I'm also running AC so that's the radiator on top. The smaller, vertical mounted one is the inter-cooler for supercharger. Yep, it was quite the chore finding space for all them.
I like the way you've run fresh air ducting to intake over the top of the radiator. I'm planning to do something similar but haven't tackled that project yet.
By the way, I do like your homemade straps. They look much better than the purchased ones. That buckle looks like brass so hopefully that resolves the rust issue.