<VV> Looking for a fuel flow sender or MPG gauge for carb engine, not EFI and not OBDII

[Larry Forman]

I have been looking for either an MPG gauge or fuel flow sender that I 
can use to make an MPG gauge for my Ultravan, Toronado powered Holley 
carbed engine.   I have found a few expensive marine or aero fuel flow 
senders and have not found any old Zemco (or other brand) fuel meters 
from the 70's.   Those might be too restrictive for a 455 engine's carb 
inlet line.    Any ideas would be appreciated so I can make some 
instrumented improvements in fuel economy.  I would be interested in any 
DIY or manufactured MPG meters for non-EFI engines and non-OBDII engines.

FWIW, my Ultravan #545 is running between 12 and 13 mpg on long trips, 
which is not to bad considering the engine, weight and frontal area, but 
I am looking to improve that regardless.

Any assistance would be appreciated.

Thanks,

Larry Forman