So when searching for replacement parts, whats interchangeable? Mainly lookin at interior and front end, suspension, windows, trim, Etc. Thanks.
All of the suspension except for rear springs, seats frames, windows, no trim I know of, some things can be made to fit, but not any sheet metal. Someone else may know more.
I’m sure that a number of folks will opine as well, but here are a few more that are different: some '67 front suspension parts, the driveshaft, rear quarter glass and rear window and related trim. Also, the non-console shift bezels were different on Mercurys.
The best pieces of advice I can give a person: (1) take a good look at what’s on your car and get the same part, and (2) don’t believe a lot of the Mustang vendors when they tell you a particular Mustang part will fit. I learned a long time ago that it might or might not. Perfect example: the LH remote control rearview mirrors. Because the Cougar’s body is shaped differently, the mirror base is different than the Mustang version, though they share the same basic mirror head shape (the Cougar’s, like all '67 and '68 Mercurys, is reversed from a Ford’s).
On the interior, things that are the same: heater/AC parts (though some of the controls/vents can be slightly different), radio and bezel, glove box doors, '68 standard consoles (others will fit but are not correct). Window cranks and door handles, some of the armrests (XR-7 armrests are unique), the XR-7 door pulls are the same as the ones on '68 Mustangs with the interior decor option. Sunvisors and interior mirrors are the same, but beware of trim-specific variations.
Basically firewall forward except for Mustang specific sheet-metal (hood, fenders, grill).
Shock towers differ in that the Cougars all had reinforcements, Mustangs only some.
Drivetrain except for the driveshaft.
Braking system other than long front to rear lines.
Exhaust: Manifolds/Headers, header pipe. muffler and tailpipe(?). I believe the exhaust system difference is in the intermediate pipe from header pipe to muffler.
Gas tank
Wheels & hubcaps
Radio antenna
Heater/AC parts
Radiator
This would be a lot easier if you had more specific parts listed. There are several interchange books on the market that would be of some help with some parts.
Okay, I’ll give it a whirl anyways. Some of what I list was already listed by others.
Interior - Seat frames, seat tracks, seat hinge covers, carpet, door sill plates, kick panels but Mustang ones will not have the speaker holes, steering column but they are different 67 to 68, steering wheels but they are different 67 to 68 and there are a few other differences Cougar to Mustang, heater controls but they are different 67 to 68, console base and some other console parts but there are differences 67 to 68, with or without A/C, and Cougar to Mustang, glove box door and insert, rear view mirror but there are 3 different styles 67 to 68.
Front end - Not sure exactly what you are refering to here. Front suspension? If yes most things are the same except that 67 Cougar lower control arms and strut rods are 67 Cougar only. Or do you mean front sheetmetal? Nothing is the same Cougar to Mustang here. Or do you mean the inner engine compartment sheetmetal? If yes then the front and rear aprons are the same. Shock towers are the same except for some 68s had the reinforced towers.
Suspension - Front is covered above. Rear is different Cougar to Mustang.
Windows - Windshield, door vent glass and frame, and door glass is the same Cougar to Mustang but there are differences in the tint on the 67 to 68 SunX glass. Mustang door glass must be from a coupe, fastback is different.
Trim - Windshield trim is the same Cougar to Mustang. While not the same some people have used the Mustang wheel opening mouldings and the Mustang rocker panel mouldings on their Cougars due mostly to price and availability.
ETC- Some of this is the same, some not.
Randy Goodling
CCOA #95
I’ll throw this in front marker lights in valance, though wired in different and the back up lights. Also brake and clutch parts, year specific. Under dash parts heater/AC box and wiper motor parking brake assembly.
Yes suspension is what I was referring to when I mentioned front end. Also, I noted it wasn’t mentioned but I figured I’d ask directly, if the steering columns are the same are the dash pad, dash itself and gauge clusters interchangeable? Deck lid? Uh…rear ends, cross members etc. So if I go to the auto parts store in a pinch and need say a front brake line, I can just say a 1968 mustang brake line? (kids my age that work the desks around here won’t know what a cougar is -_-)
Probably best to compare 1968 Cougars to 1968 Mustangs if that is what you have.
There are lots of differences between 1967 and 1968 Cougars.
Steering and front suspension wise, Cougar and Mustang are the same for 1968. Lots of suspension and steering differences between a 1967 Cougar and a 1967 Mustang. Early and late differences on power steering for 1967 Cougars too.
The front park lights are actually 65-6 Mustang and 67-8 Cougar.
Randy Goodling
CCOA #95
Dash pads will interchange 67 to 68 but there are some cosmetic differences. They are Cougar only. There are some differences between 67 and 68 dashes and gauges. Some parts will interchange. 67-8 deck lids will interchange but there are some cosmetic differences on the underside. Rear ends and crossmembers should all interchange with allowances for 8" or 9" rear and which transmission for the crossmember. Sounds like it is time for the counter people at your parts store to get an education on what a Cougar is. Make them earn their paycheck.
Randy Goodling
CCOA #95
Yep, my bad Randy.
The counter people need an education on cars in general 
one of my friends works at an O’Reillys and I’m pretty sure he’s the only one who drives a v8 car. He pretty much was raised like me except his parents are just general car people and don’t work in the auto field. His first car was his grandpas 69 Lemans lol. Anyway, only reason I asked about the dash parts is I googled cougar dash and gauge clusters and Cj’s and summit bring up mustang ones. I figured if they would swap out easily there’s a bigger mustang market to find cooler stuff, or cheaper. Oh well. Thanks guys I saved all the items on a word doc.
Hello,
Can anyone tell me if the statement below is true?
“Exhaust: Manifolds/Headers, header pipe. muffler and tailpipe(?). I believe the exhaust system difference is in the intermediate pipe from header pipe to muffler.” (RKTMN)
I am looking to replace my exhaust and wonder if I buy the Mustang setup, can get a piece of pipe welded in to extend the pipes to fit correctly?
Paul
You should be able to check the part numbers for an exhaust at NPD or Mustangs Unlimited. Mustangs usually had transverse mufflers Cougars had dual mufflers on dual exhaust cars. So the Dual muffler systems for most Mustangs are not origional style. The engine pipes are the same on both cars.