SBM MPG Challenge

Well I plan on pulling the 360 out of my car and putting it in a dakota r/t body style with a 2.45 gear or 2.76 with about a 29 inch tire. It should weigh around 3,800 and will be lowered. With EZ efi feeding the OOTB eddys and a small flat cam do you think 20mpg is achieveable at about 2k rpms at 70?

PS Diesel is killing me.