As far as value - I think that a good starting point is NADA average retail. Add or deduct from there. One option that does not get enough attention is disk brakes. To be up front I perfer 302s but would love a 428CJ. Ok so don't beat me up - I can't say what I'd sell for without seeing a car so theroreticly all options being equal this is what I would pay for an unrestored driver (no mecanical work required) disk brake 4spd / auto (NADA):
CJ 428 - 75 (28.3) / 70 (26.5) (Bob I'll pay WHAT YOU SAY! put me on list)
s 390 - 25 (22.8) / 24 (21) (to low)
x 390 - 19 (21.9)/18 (20.1) (loved the black e-bay highway cruser)
j 302 - 19 (21.9) / 18 (20.1) (just noticed they have same NADA price)
c 289 - 15 (20.1) / 14 (18.3) (bias - rather have a 302)
t 200 - 10 (16.4)/ 9 (14.6) (I do have a secret desire to drive a 200 4spd)
The one option I love is a bench seat. If you owned a 68 bench Tu Sabes. I put my numbers down before looking up NADA. Humm.
Holmes, you brought up a couple of good points without even realizing. Tu sabes? LOL I read right through that the first time and didn't catch the spanish phrase.
Check Applicable Options and Equipment:
302/230 HP V8 Engine
390/265 HP V8 Engine
390/315 HP V8 Engine
4 Speed Transmission
428/340 HP V8 Engine
428/360 HP CJ V8 Engine
429/360 HP V8 Engine
6 Cylinder Engine
Air Conditioning
Mustang Pony Interior
Ram Air
The above is a C&P from NADA Classic Cars for both the HCS and GT/CS. That information is too general and leads folks to believe some falsehoods.
All 1968 R code 428CJ's are Ram Air. Ram Air was not an option with any other engine in 1968. (Q code, non-ram air engines came out in 1969)
429/360Hp that engine never came in a 1968 Mustang.
4 speed transmission only available factory on V-8's.
Holmes, the disc brake thing is what got me to thinking. NADA incorrectly assumes that all GT/CS's in 1968 received the GT package which I believe included disc brakes.
They also left off the C code 289 engine too. Horsepower ratings mostly incorrect too.
What, no automatics? 3 speed manuals were standard on all but the R code 428CJ.
Mustang Pony interior? Please, not since 1966. Can I get a Deluxe or Sports Woodgrain trim?
This exactly illustrates what I mentioned way early on this thread.
NADA needs help to get it right. I am sure that they strive to get it right, maybe they need some one of us to gently suggest that their "Applicable Options and Equipment" check off boxes aren't as correct and accurate as they could be for any 1968 Mustang let alone the GT/CS and HCS's.
Additionally to value these cars, certain other options add value; tilt-swing steering column, console, convenience control panel, AM/FM or AM/8track stereos, disc brakes, tinted glass, vinyl roof, GT package, locking axle, power steering, cruise control, headrests, tachometer, and clock. And the bench seat.
If I could suggest a change to NADA, it might look something like this:
200-1V/115Hp 6 cylinder engine
289-2V/195Hp V8 engine
302-4V/230HP V8 engine
390-2V/280Hp V8 engine
390-4V/325Hp V8 engine
428CJ/Ram Air 340Hp V8 engine
Automatic transmission.
4 speed transmission.
GT suspension package.
Air conditioning.
Power steering.
Disc brakes.
Deluxe interior.
Deluxe woodgrain interior.
Tachometer.
Console.
Tilt-swing steering column.
Cruise control.
Headrest seats.
Factory AM/FM or AM/8 track stereo.