Thanks guys as usual with me buy first research after!!! Hopefully with it going on a crew cab I've got a bigger area,after I bought it somebody said the floor cut is different width on ribs,pick up next week will let you know how it looks
I've done one into a split, I used the reinforcing bars either side of the engine bay to decide the width of the hatch, no need for a steel box section.
I had to make it narrower, I offset the join to keep the strength and make it easy to keep flat, ended up with a slightly wider rib in the middle , but much easier than building a frame