while i love the idea of converting an old truck to electric, and there are a few sites about people who have done it, i gotta say that if 95% of your travels are 1-3 miles... suck it up and ride a bike, or walk.
on a bike you can cover 3 miles in less than 10 minutes easy... do you really not have enough time in your day to spare that? or enough warm clothing to be out in the rain or cold that long? i can go a mile on my bike in the time it takes me to find a parking spot and walk in the store sometimes.
as for carrying stuff, you can get a trailer
panniers
or even an xtra-cycle
it's your money and you can do what you like, but there are those of us who do 10, 20, even 30 mile daily commutes to stick it to exxon et al, 1-3 should be no problem at all.