5th wheel placement for hauling containers

I don't know what area you are located in, but I would say check with your local truck salvage yards and think about upgrading to a slider. A fixed fifth wheel kinda limits your ability to pull different trailers and scale the truck legally

 

The end of your frame sticks out farther than necessary looks like the very end is where it is closest to hitting.just cut it back and and mount the mud flaps farther forward
The other thing is it looks like your fifth wheel may be set too low they come in 4 heights usually 7,8,9 and 10 inch heights to see what you have put a 3 foot Level on your fifth wheel plate and make it level then measure to the top of the frame if it is 7 or lower you can raise it without much expense, I think the highest you want a fifth wheel to the ground is 52 inches if you are less than that you can raise the fifth wheel without having to worry that the trailer will end up too tall.
a sliding fifth wheel is great but in your case with the back of the frame in the way the only direction you can slide is back

 

Looks to me like you need to move your fifth wheel back about a foot. Get your truck frame way farther away from the trailer frame or next time you turn a corner on uneven ground you'll be ripping that frame again.

 

About a foot back is right. That's up real far. I personally like it 6-8 inches back of center but most of my loads are light. About centered or a few inches back of center would be good for what your doing

Edit: doing containers you prob want that AT LEAST 8in back of center to avoid any issues. Getting some weight off the front it'll ride a little better too

 

I have a fixed 5th wheel also, on a 2013 freightliner pulling containers. My 5th wheel pivot point is set exactly between the drives and I’ve never had an issue with catching my frame with 40 or 20 footers. Also surprisingly my steer weights consistently hover around 12000 fully loaded with it set right there.

 

When I was pulling containers I had a mechanic shop cut down the top of the frame from behind the fifth wheel to the end .
and weld a flange plate back on top of the frame .

was either that or get a different tractor .

some of the container chassis just hand down really low and hook the tractor frame .

also a
Sliding fifth wheel is very handy for shifting weight from the drives to the steers

 

you don't need to get a new fifth wheel move the fifth wheel back to center if that is what will work most of the holes will line up you may need to drill 2 to 3 holes on each side using carbide tiped hole cutters easy to do with a hand drill and use the holes in fifth wheel flange as your pattern.