Engine swap?

Myself, if I could get the 350 for no more than what it would cost to rebuild the 307- looking anywhere from $1000- $1500 for the rebuild I would have to go with the 350. You may have a decrease in gas mileage but an increase in get up and go. But thats me, I like the power, as I have a 350 in my 1971 chevy truck. But I would make sure that the 350 is what it is said to be. You can get a new crate motor -350- for $1500-$1800 - with up to a three year warranty if you shop around for it. So I guess it comes down to how much you want to spend and if you are looking for a little more than the 307 will give you. Good luck.