Flo scan mounting
I had the same question for my EIS 4000 flo scan and decided to mount mine on the floor about 12" from the firewall. I am running a carb and I relocated my facet pump from the firewall underneath the fuel selector similiar to the F.I. folks. I also put an EZ flow filter in line to the boost pump on a modified F.I. pump base from Van's. I ditched the gascolator and ran the fuel tubing through the firewall directly to the engine fuel pump via a fabbed up aeroquip hose.
Many folks suggested placing the flo scan in the engine room, but keeping it out of the heat seemed like a better option to me as many F.I. guys are doing the same. You will have to make a little cover to conceal the flo scan as it will stick up above the center tunnel a bit.
Jeff