SBC Swap
Unless you're rich , the reduced V-8 fuel economy will pi$$ you off .
That being said , there's simply scads of rebuilt or Target (means : heavy duty 4 bolt mains etc.) 350 engines in the Pick-A-Part yards for $350 or so complete , carry out fan to flex plate .
The smart money goes with the automatic overdrive trannies , makes it easier and more fun to drive for most , plus adding AC is a breeze and it won't slow down when the AC compressor cycles like an I6 will .
I even see Corvettes with the batter 350 and fuel injection , those get pretty good fuel mileage and run *perfectly* all the time , cold , hot , AC on/off , loaded empty etc. .
Me , I think since you apparently don't ever drive it now ,the I6 makes more sense but you are paying for it so follow your heart .