86fox-
If you have an aftermarket ignition, you're still not gaining anything by having the quad tipped plugs, just using good quality plugs that have good ceramic insulation (so it doesn't arc through and ground directly to the block). I personally hate Bosch spark plugs, i've had them in three cars and in every car there were misfires because some of the plugs would have arcs through the ceramic (yes, through that porcelain insulation part) and some of the tips would transfer an excessive amount of metal from the tip and increase in gap by itself over time very quickly because the tip is very skinny. I've never had any problems with autolites and i personally now always buy Motorcraft plugs if i can.
I suppose the best answer i can give you is that most aftermarket ignition manufacturers make their own low resistance, durable plugs designed to handle the higher amounts of amperage [jimberg, i've studied electrical theory (Have ASE certification in electrical auto systems) and learned through the "plumbing analogies" as well
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'84 Mustang 5.0 LX
My car