[Brad54]

I worked in car magazines as a tech editor for 20 years... I've never been able to find the math that makes EFI a good investment in terms of fuel economy over selecting the correctly sized carburetor and tuning it.
$1,500-$3,000 (or more) for a kit, plus tuning equipment, installing EGR, etc etc, and then break down the cost of getting a couple more miles per gallon.
Say you got 3mpg more (which is doubtful versus a properly tuned carburetor)
How many tanks of gas is that going to save you over the course of a year.
Not as many as you think, once you start doing the math.
Not on our cinder-block shaped vehicles.