If the holes in the gaskets are smaller than the plate holes you drill out, then the gaskets would restrict the flow. There'd be no point in drilling out the holes in the plate! I just installed a TransGo shift kit in mine, & had to drill out several holes in the plate. Very similar to the j-mod. But the gasket holes were plenty big enough, & didn't need drilling.
Not sure where the 7D100 # comes from. But you should be able to get the right gasket from your local Ford dealer.
Don't forget to check your 1-2 accumulator. If it's the aluminum type with the 2 thin o-rings, you'll want to replace it with the later design. (p/n F7AZ-7F251-AA) Made ALL the difference in the world in mine.
Hope this helps,