I don't know about the kits, but NG coming into homes is a much lower pressure than propane (the b*st*rd gas as hank hill says). Hence the larger holes for gas stoves, heaters, and grills than propane.
I've rigged up crawfish boiling pots on NG and I only had to bore out the holes.`
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Right now I have2006 2500 MegaCab 5.9L Automatic. AFE Stage 2 & 5" Silverline Turboback.
I want to get I don't know what I'm getting next, give me ideas