This shows the welds' locations in relation to the lip of the channel. Cut behind this lip; the front edge of the hole can be an inch or so behind the welds to avoid the lip of the floor support channel. You can always cut the hole too small, and then enlarge it as-needed. But if you cut it too large, the plate won't cover the hole, so always start small.

This truck has a body lift, which is why there's so much room here.

Owner caption April 2006 · Photo 1244 of 5000