5.9L Magnum questions

And the saga continues...anyone have any issue with getting Comp 901 springs to sit down on the stock seats? I kinda thought that these springs were drop in's on stock 5.9 iron heads. I measured the stock spring base dia. at about 1.316, the 901's are 1.494. Anyone have to take a grinder to open up the "ledge" created by the seat cutter to get their springs in? Looks like what it's gonna take. Any answers appreciated. Thanks.