hey buddy,
if u wanna see some pics of autometer gauges have a look at malcoms yellow fb in "share your pics of interior" page 2 looks gr8. custom made tripple gauge pod sitting where your heater instruments normally sits i rekon a 5inch monster would sit nice in there along with water, oil, pressure.
I know the Autometer speedos fit the FE/FC dash, all I had to do was make a 12mm MDF ring for a snug fit. Not sure how you'd go with the bezel in the FB/EK dash, why not take a bare dash down to your local Autometer supplier and try it out.