Aftermarket cross channels for subrails need to be cut?

[ModelAJim]

Does anyone know if you need to cut-to-fit the cross channels that go to the subrails you get from Snyder's Bert's ect?

I laid my new subrails out on the floor with the rear subrail where the panel below deck lid bolts too but the cross channels that's seperate the floor pans they seem too long and all same length??

I feel like I have to bolt the subrails to cowl then the rear cross member where panel below deck lid goes then cut the others to width.

Sound right or no?