recessed tip spark plug options for big block

I'm trying to find some recessed tip spark plugs so I can try some nitrous. I'm using 452 heads and all the ones I have come up with while searching are extended tip.

In the .375 reach, not as many choices out there. I run NGK almost exclusively these days. Their race plugs, while considered extended tip, aren't nearly as far out there as others.

In my beater motor home 440 with 185 hp hit, I had no problems, and drove it on the street.

From Hot to cold
R-5670-6 2746
R-5670-7 2891
R-5670-8 3354
R-5670-9 3913

Thanks Billy. I guess that explains why I've had so much difficulty finding some. Currently have plate jetting set for 100hp but will eventually plan to work up to 200.