I'm sure the aftermarket EFI systems are very nice and tuneable if you want or need that option.I think it's hard to beat the factory stuff for reliabilty and no messing around.The factory has spent tons of time on r&d for this type of stuff not to mention all the years us consumers tested it under all different circumstances.I didn't want to mess with a laptop for fuel or igntion curves because I didn't modify the motor at all in my wagon,other than headers and ditched the egr stuff.I found the engine and trans on craigslist with 37000 miles on it.I purchased the ford racing harness and it was running in no time at all,total plug and play,very easy to install.The harness is not cheap 600.00 at the time,but well worth it to me,wiring is not my stong suit.The wiring was done within a hour if that.The fuel system took awhile longer because I ran a in tank pump and ran hard line front to rear,with a short piece of flexable aeroquip from the line to the rail.I love the setup that I have,I put over 5000 miles on last year and just shy of that this year.I have not touched the engine other than a oil change.Oh lets not forget it's getting 18-19 mpg in a 57 four door wagon,and I have a heavy foot.I'm sure it would be in the low 20s if I drove normal.All my other cars have carbs and they don't scare me plus I know my way around them,but the wagon by far is the easiest to drive in any condtion or temp.I'm not going to convert any of my other cars because I like them a little more tradtional,but I do highly recommend a efi project of some sort.
Have fun
Joe