Is there a vendor that sells the correct bumper bolts for my 71 Charger R/T? I'm making an assumption that there's a difference between the ones that came on our cars to ones that came on every other chrome bumper beast from the previous 70 years.
What are your thoughts?

Any feedback guys?.
I know there's some aficionados out there with some direction for me.

Really all you need to buy at the vendor of your choice is stainless FLAT head bumper bolts. You can do a quick polish to them before installing and they will last a lifetime.
R T Specialties is a good place to get them or on ebay.
Ron

Understand your questioning, and hes right- just buy stainless and polish them. Otherwise, you need to pay someone to showchrome your bolts to match your bumpers. Polished stainless and rechromed do look slightly different. Whats it worth to you?

What about the head diameter. What would be correct?

Years ago I bought some NOS from Richard Ehrenberg from his eBay store.
Link to eBay site.