To Girdle Mains or Just Studs

Studs are probably adequate with those heads, aluminum caps seem to help too. The BCR cap & girdle system is the full bore setup, but probably exceeds what's required.

http://www.bcrproducts.com/caps_and_girdle_system.html

A common issue with the stock caps and fasteners is usually fretting.

I'm doing studs with aluminum caps on my current 451 build; in fact, I'll be align boring it tomorrow if all goes well. S/F....Ken M