Yeah I gotta agree with the no replacement for displacement. Put my vote solidly there. Nothin' wrong with a 305. You can make them plenty strong, but if you've got the choice pick the cubes. More easily attained power, both torque and ponies, and believe it or not, the engine kits are generally a little more expensive for a 305. You'll probably see better mileage with a 350 too. The better the power, the less the engine has to work to propel your ride.