Big block spark plugs?

[EvilScamp]

I putting together a 383 for my Duster and i want to use Platinum plugs or even double platinum.
The problem is i'm having trouble finding them, so far the only thing i can come up with is champion 3405 platinum.
Anybody else using something different? Part numbers?

 

[oldkimmer]

.............There prolly isn't much choice seeing how the last bb rolled off the showroom floor in 1978.............kim........