We have run 4 different alc. set ups on our cars
1- Blown SBC (Injected) fuel is drained from the tank+lines after every weekend. Pump Barrel valve are WD40'd. Lines are blown clear of any fuel left over and then WD40'd and we use air to blow the WD thru.
2- Injected SBC. everything as above
3- Carb BBC. the same
4- Injected BBC I have done exactly as above and had no problems with alcohol residue. Then I started adding Klotz to the drum of alcohol when it was delivery to the shop. If I am running back to back weekends, I'll leave whatever is left in the tank to warm the car up the next weekend. If the car is going to sit longer I drain all the lines and the tank. I might even give the pump and barrel valve a shot of WD40.. I have had no problems this way again. The only funny thing I see is that whereever the fuel flows. from the nozzle into the head into the cylinder is a light shade of pink