I need some suggestions for my FI project

[81xsproject]

I do have the original/large size box. Just like my MSD box I had, I am thinking it will go behind the battery. The msd was even larger than MS.

[Shappers]

Here's another picture for you, just to keep your options open.

By moving the regulator forward you free up a large chunk of space where you could mount something. One of the UK guys found a gel battery that fitted nicely into this space, I fitted my Mini-MS box.

Just note, my tank didn't fit after I moved the regulator I had to bolt it on from the underneath to get the tank to fit.