4 row radiator, gap @ bottom of shroud

[Greasey Harley]

I recently replaced the radiator in my '68 with a 4 row from a big block truck.
I also replaced the radiator holding cups, and top clamps, with the bigger ones.
I had to slightly modify the core support, (a couple small notches) to accommodate the larger bottom cups.
With this new setup, the bottom of the fan shroud won't bolt op tight to the core support, it leaves about a 1/2 inch gap.
I have a couple questions.
1- Did trucks with 4 row radiators get different core supports, to accommodate the larger cups and shroud gap.
or,
2- Were the core supports factory modified and a slightly different shroud used?

It's not a big deal. nothing a couple spacers couldn't solve, I was just wondering