You can run the 12:1 FMU, but you are limiting your fuel curve. I suggesst you drop the FMU and pick up either a V-AFC, or an S-AFC, and some larger injectors. I have some RC. eng. 310cc injectors for sale right now if you are interested. E-mail @ Cazan82@aol.com if you are interested.

Anyway, when you have larger injectors you will no longer need the 12:1 FMU, becuase you now have the injectors, but you will need a AFC of some type to tame your 255 intank pump, and larger injectors. You will be able to due all your fuel tuning/taming w/ the V-afc or S-AFC.

So i suggest this:
High flow intnk fuel pump, either 195 or 255.
Larger injectors
missing link
S-AFC or V-afc

Thats all you need for your fuel tuning, and it's ALOT better then the FMU route.

hope this helps.