I too just installed a Holley EFI sniper over the weekend, like one user posted, installing the fuel pump/ lines,return line took longer than installing the EFI. So far I’m very impressed with the startup, acceleration etc. I couldn’t tell you about any mpg increase though. A question I have for the ones that have installed a sniper efi... what did you do about your timing? Or what is your timing set at? I’m using the distributor setup (-coil) but thinking about going HEI soon.