With the prevalence of swapping in T-5's I think the fact that a car was originally 4 speed does not have as much bearing on value today as it used to. It's nice to have a 4 speed from the nostalgic standpoint, and I sought out my vert to be a 4 speed (20 years ago) but I think the market for original cars is one that continues to shrink. While it is nice to have the pedal setup already in the car, a 3 speed car would afford the same thing. What you have to consider is what you want to do with the car; If you are going to mod it, then look for one with the basic components that go with your plans; if you are going to restore to original then get one with the options you want. That being said, most people will ask more for a 4 speed car just because it still holds that mystique.
for someone like me that only owns stick cars the 3 or 4 speed stick is worth more than an auto. i can always swap a 4 speed in. i know guys with automatic mustangs here in los angeles and they made comments to me about how stupid they think it is to own a stick car of anykind and drive in the traffic in la. my dad lives in missippi and even made comments about me buying a truck with a stick. his 66 mustang is an auto. i would say it depends on what the buyer is looking for. if the buyer wants an auto then its gonna be worth more to them than a stick. i have seen lots and lots of 65-66 stick mustangs. all my 65-66 mustangs were stick cars. a 5 speed is worth less to me then a toploader equipped mustang.
My car has a TKO 500 in it, which I put in myself by choice. If I walked up and there was a 3 speed car, converted to a tremec, then an indentical one but was factory 4 speed, I'd pick the TKO hands down, even if it was original. To be honest, originality holds no bearing to me or most people I know. I like to know what it was, thats all well and good. But to me it comes down to what it is at this moment.
I like them the way they came, and that being said here is the reality of the car market, as I see it. I grew up when these things were new so that has a bearing on what I like, but most other gear heads see them as a platform to improve on, and there are many improvements that can be made on the old "straight line cars" The resto mods seem to run, turn and stop better than what a restored to original does, and if the Barret jackson is any indicator of value (I'm not sure if it is, but you can't deny the prices their clients pay for the cars at their auction like the 141K for a worked over 1955 chev pick-up), restomods sell for more money in most cases, at least at auctions. I have always felt that you can restore it 100 times, but it is only original once.
If I was doing one today I would trick out the engine, trans and suspension so it would hook up, go fast, stop and turn, but look like an origional. Just my opinion
first off i prefer a close ratio for roadracing and the t5 ratio is too wide. i dont like overdrive cause for 1 the spur gear is weak and overdrive causes some power loss compared to the underdrive and 1:1. Jericho makes a roadrace 5 speed with a 1:1 5th in a multitude of ratios. the problem with that 5 speed Jericho is 9310 non-heatreated gears will last about 5000 miles on the street along with the dog type slider sytem according to Jericho. If Jericho made a street version i would have it for my torino. i dont have my toploader because i want originality i have it cause it does exactly what i want it to do and that big input 31 spline out had no problem handling the 600 hp of my big W ! i also like the fact that it shifts soooo smooth and easy and i can put the shifter right next to my leg. if i ever bought another mustang and it had a t5 or other 5 speed i would pull it out and have it be gone. if a t5 turns you on more power wait maybe i should say a little power to ya ! it all comes back to what the car buyer wants. i stick is worth more to me casue i dont have to go buy clutch and brake pedals but some people only drive auto especially those that never learned to drive a stickshift < my cb handle !
if I'm ever buying an old car that I want to keep, at least for a while, I look strictly at 4 speed cars. I'm 54, but just never grew out of loving to swap gears.
I don't know how many times, but it's been a bunch, when some guy will look into the car and say something like....."and it's a 4 speed too. cool". You don't often get some guy peering into a car and saying "wow. And it's an automatic." No offense intended to anybody that likes an automatic transmission. It's just an observation.
I just sold my 67 GT390 4spd coupe today. The guy told me he wouldn't have considered the car except it was a factory 4spd. 90% of the guys I deal with always want a 4spd. The sell for more money and faster. Personally, I really like the 5spd for a street car. Sure makes driving the hwy nice.