Sure, the car with the updated drivability mods is better and worth more to a buyer familiar with 4.6L MN12s, assuming those mods were all done properly. In this scenario, an appraiser's word is hardly the final determination of a car's value, but I'm not sure any of those mods move the needle much either way with the mileage at 100K. At that point, it's clearly being treated as a car, not an artifact. Now, if someone made those mods on a car with only 10K on it, I would first question why, and second, I have no idea what that does to its value. I'm not saying it's never happened, but I doubt that type of scenario has played out for these cars to even think about it.I’m not active there to know, I’m just going by the quotes and dredging past discussions on the subject.
Modified cars are kind of a weird thing with values, I don’t think it’s quite as clear cut as modified = worthless, untouched = $$$$$, it really depends on the car, miles on the chassis, what the modifications are if there are any and how well they were done. I agree that there’s not celebrity builder aura in most builds but a base inline 6 1969 Mustang fastback probably won’t have its value negatively impacted by having a 408 stroker swapped into it, whereas a more coveted Mach 1 probably would.
Right now I think low miles trumps all with regard to MN12 values, but that’s a finite and difficult quality to maintain unless you don’t drive it, and is pretty irrelevant to most of us in the club should we be concerned with cashing out on our “investments” 😆. So, ponder this choice, 100K mile V8 LXs or XR7s, equal as far as body and interior condition and maintained, would you pay more for one that’s stone stock, or one that has a PI engine swap, J modded newer trans, Tokico shocks and PBRs/rear disc swap? Appraisers might scoff at the latter but I bet they’ve not evaluated the market the cars appeal to.
There’s always been some modicum of accepted liberties In the collector car market, dual circuit brakes, alternator retrofits, smog device deletions, blueprinted overbored higher compression engines within the “numbers matching“ blocks, radial tires, adding an option like a spoiler substituting an option like using dog dish caps rather than the original styled wheel covers etc. All this and the examples I used pertaining to us is a far cry flame paint jobs and hydraulics that are much more about personal taste
Of course this won't apply to most of us with the degree of mods that we have. It's not an investment, it never was, and if one ever thought that it was, that person has been living in their own world.
Ultimately, all this is to say that these things are indeed nebulous to a small degree, I don't really know how to value our cars but I can tell if it's blatantly off-target, and I still don't really think of them in the same way as I do with older cars that we grew up seeing on televised auto auctions. But when people on the Internet argue whether a particular used MN12 is worth $3000 vs. $4500? Even though there's a 50% difference in those values, I still don't care.