Same considerations come in to changing the engine out for something flashier or with more HP or doing a color change only, maybe, to a lessor amount or degree.
Since your only asking about about value then this has nothing to do with if you will enjoy one choice over the other just the bottom line counts. Considering only that you will likely turn some buyers off to a purchase completely, reduce what they might pay for the complete car (deducting dollars and effort costs) while some others not concerned about originally consider the car. Consider that there are allot more other options for buyers in the later category - slightly unoriginal to very unoriginal than there are the other way around.
Looking at your prior posts
" So far for upgrades I replaced the rockers with scorpion roller rockers, added headers, installed pertronix III in the distributor & have an edelbrock 600cfm carb. I would also like to put in a bigger cam. "
Looks like you've made the choice already so you might want to ask members of a forum focused on driving and making improvements if the additional changes would decrease the cars value in their eyes since those are more likely who you will be selling the car to.
NOTE: this thread was moved over to the General section since it is a question often asked on other sites and is not IMHO really about the fold down option but the overall plan for the car. The fold down is only today's focus