Hope this helps Steven

I put the cans towards the rear of the space with the lid to the front

I have them on both sides of the van the left one will lay over the AC hoses and needs the white spacers.

I used 4 bolts to secure them. i first got them in place with a jack
and then drilled down thru the floor depressions  and the can top. Bolts were 
secured to the can and jacked back in to place and secured.
Then the excess bolt was cut off. 

View of floor. I cut some of the foam and filled it in.

I removed the snap latches and welded some connecting nuts to secure the lid.
To get the right spacing I welded one nut and then another to it.
The can is 2 to 3 inches higher that the prop shaft cover on my Syncro.

I used safety allen bolts to secure it. Nice Safe when you leave it at the trailhead.

 
 Bob

86 Syncro 
91 Westy