AC Delco Spark Plug 46N alternatives

[thelawdoc]

Guys, I went in to an auto parts store today and asked for 6 Delco plugs, 46N. The guy says he is out of Delco plugs and gives me Denso plugs. The Denso box, containing 4 plugs, is marked: "W16EXR-U#4 / 3031#4 Resistor D9". I ask him how he knows that the Denso he is giving me can replace the Delco 46N and he says "the computer says so." Ok, I get home and I look online and I find a conversion chart for the 46N and on the chart it gives the following Denso choices:
Denso W16ES-U
Denso W16ESU
Denso stk 3025

So I am wondering. Firstly, am I correct that AC Delco 46N is the correct plug for my '66 250 I6 (carb&distrib)? Secondly, did he give me a proper alternative?

Thanks.
Alden