Vintage Mustang Forums banner

Status
Not open for further replies.
1 - 20 of 86 Posts

·
Registered
Joined
·
88 Posts
Discussion Starter #1
Hello all,

i have a 1968 Mustang coupe that i am restoring. i am a newbie and doing everything myself (paint, body, and so on).

i purchased the car with a 289 engine and automatic transmission - i believe it is your standard C4 transmission.

here is a link to my documentation site:

https://picasaweb.google.com/geeky2

someone has asked me if i want to buy their 390 engine and swap out my 289 engine (that came with my car).

1) will a 390 fit in the engine bay of a 1968 mustang coupe?

2) he wants to sell the engine for 150.00. is this a fair price?

also - are there any other considerations i need to take in to account?

for instance - do i have to find a new transmission to fit the 390 engine?

ANY advice or guidance would be greatly appreciated.

thank you,
mark
 

·
Registered
Joined
·
3,355 Posts
Yes the 390 can fit in a 68. Thank god you didn't say you had a 65-66 because you'll get the 3rd degree from everyone about having to cut out stuff to make the engine fit. As for being a fair price, sounds fair to me. Not sure about anything else. Not too familiar what the needs for 390.
 

·
Registered
Joined
·
618 Posts
Yes it can be done, all the parts to do the swap are available. The 390 has a different bellhousing bolt pattern than the 289. Most auto trans for 390/FE engines were the C6. There maybe a bellhousing for the C4 that bolts to a 390, but the C4 will need to be upgraded.

I put a 390 and 4 speed in my 67 coupe. Starting from scratch, buying all the necessary parts for the 390 adds up quickly, but IMO its was worth every penny.
 

·
Registered
Joined
·
4,929 Posts
$150.00 for a running 390 ? sweet price i just paid $100. for a rebuild able long block 390 and thought i got a deal . i 'd buy it even if you decide you don't want it ,you can turn a profit easy . just make sure it is a 390 not a 360 or 352 .they all look the same from the outside, only diff is bore and stroke . 390 is 4.05 bore and roughly 3.75 stroke
you can measure stoke with a wood dowel thru the spark plug hole 3.50 stroke =360
 

·
Registered
Joined
·
9,844 Posts
Sorry, I'm not going to jump on the 390 bandwagon.
Antiquated, heavy and so-so mileage. (I'm now zipping up my flame proof suit)
You'd be better off building a 289, 302 or stroker engine.
By the time you upgrade everything (like you really should) to run
a 390, you're better off going the other way.

A well sorted 289/302 with a C-4 is more than a match for a 390 with
a C-6..... any day.
 

·
Registered
Joined
·
2,326 Posts
The cylinder heads for a 390 in a Mustang are different than the more common ones used in trucks and full size fords. The difference is in the number of bolts for the exhaust manifold. Full size fords have 8, one above and below each port.
Mustangs have 14 I think. To run the stock exhaust manifolds for the Mustang you MUST have the correct cylinder heads. If you are willing to run long tube headers you can use the more common 8 bolt heads.

Bottom line, the 390 is a bolt in engine in the 68 Mustang. But it uses almost none of the parts you all ready have to bolt in. If the 390 came from a Mustang and you could source all the parts in one place it might be worth the hassle. It depends on what you want out of your car.
 

·
(actually Slim Jr now)
Joined
·
24,597 Posts
Mustang was widened fot 67/68 (same width as the first Cougar which was 67) specifically to allow the 390 engine(s). Many 67 and 68s were built with the 390.

The 390 was used in many Fords including the T-Bird, LTD most were manual tranny or
C6 tranny and depending on application accesory mounts as well as bell housing may be different as JDM said.

Make sure you and or your mechanic has checked all these "details". It's not just a simple 1 for 1 swap.


Slim
 

·
Registered
Joined
·
3,993 Posts
In comparison to the 289, in increased weight also reduces the handling...the SB will feel more nible.
 

·
Registered
Joined
·
87 Posts
Sorry, I'm not going to jump on the 390 bandwagon.
Antiquated, heavy and so-so mileage. (I'm now zipping up my flame proof suit)
You'd be better off building a 289, 302 or stroker engine.
By the time you upgrade everything (like you really should) to run
a 390, you're better off going the other way.

A well sorted 289/302 with a C-4 is more than a match for a 390 with
a C-6..... any day.
+1

Stick with the 289, it is a better engine for the Mustang. The 390 was a truck/boat/"full size" car engine. The 289 is a sports car engine with racing heritage. The first thing Carroll Shelby did with the 390 was remove it from his cars. ' Nuff said.
 

·
(actually Slim Jr now)
Joined
·
24,597 Posts
If you're not a big block fanatic (yes fanatic) I'm another long time Mustang nut wearing a flame resistant suit. The 390 was an old engine in 67 but brute power to compete with Camero. If you like to do your own underhood work you may soon dislike it unlike you love knuckle busting challange of wrenching it tight places.

The 302 and 351 are "small blocks", easy to work on and less antiquated.

I'm a converted small block fan. In 55 Chebby introduced the "modern" small block V8. AIRC it was 263 cube lightweight valve train, big valves and revved like crazy!

Around 61 Ford had their version of the lightweight small block. The 260,289,302 and 351 are versions of that design.

I would recommend you evaluate carefully before jumping into a 390 swap. Where is it from, what condition, do I really want the big block, what all needs to chance etc.

Slim
 

·
Registered
Joined
·
148 Posts
Save yourself alot of headache and build yourself a small block to put in the car. It will handle a lot better, its alot lighter, easier to work on, cheaper to build. FE engines are a different animal all together. If you dont know anything about them (like most machine shops) its better to stay with the 289 or windsors. You will have all kinds of issues with headers, having to change the coil springs for the added weight, and upgrading the cooling system to keep it cool. Im not knocking the 390 by no means. I have a 1969 Mach 1 with a factory 390. I love the car. Just trust me on this one and stay with the small block if thats what it came with.
 

·
Registered
Joined
·
784 Posts
OK...

Dream On (just kidding, no offense meant)

(I'm now zipping up my flame proof suit)

A well sorted 289/302 with a C-4 is more than a match for a 390 with
a C-6..... any day.
Good thing you got the suit on... :)

You can get a kit from Survival Motorsports to get 445Hp out of that outdated old engine without getting carried away. And in general if you put the right cam and valve train in it, it will wind as high as you want it to. FE engines are different, but I have not seen anything so different that common sense did not prevail. Also, if you put the Edelbrock heads and manifold on it will probably weigh less than a stock 289

You'll need different motor mounts and maybe a little more work, and it is a tight fit. If you want to ask some more advanced questions, the FE forum http://www.network54.com/Forum/74182/ will throw answers at you fast and furious. There are experts on this forum also, but the FE forum is all FE's
 

·
Registered
Joined
·
5,674 Posts
Yes.



And a "well sorted" 390 will go 600+ HP and massive torque, without too much effort. So depending on the "match" strip or track, results may vary.

Check out Suvival Motorsports for what you can do with an FE...

Survival Motorsports Home Page
 

·
Registered
Joined
·
87 Posts
Dream On (just kidding, no offense meant)



Good thing you got the suit on... :)

You can get a kit from Survival Motorsports to get 445Hp out of that outdated old engine without getting carried away. And in general if you put the right cam and valve train in it, it will wind as high as you want it to. FE engines are different, but I have not seen anything so different that common sense did not prevail. Also, if you put the Edelbrock heads and manifold on it will probably weigh less than a stock 289

You'll need different motor mounts and maybe a little more work, and it is a tight fit. If you want to ask some more advanced questions, the FE forum 332-428 Ford FE Engine Forum will throw answers at you fast and furious. There are experts on this forum also, but the FE forum is all FE's
O.K. But if you are going to be investing that much $ in mods, you could do similar mods to the 289, add a S/C and clear 400HP with a h*ll of a lot less weight on the front axle (exactly where you DO NOT want it), not to mention sparing yourself the huge additional weight drag from the switch to the much heavier and less efficient C6 (if you stay with AT).

Oh yeah, and you could still turn a corner at more than 20 MPH if you keep the Edsel motor out of the car. LOL
 

·
(actually Slim Jr now)
Joined
·
24,597 Posts
Excuse me for apparantly misreading the OP. My impression was he was asking if the 390 swap was doable, will it fit and suggestions/advice.

Didn't read anything about drag racing, track racing, which would handle better etc. I gave my honest opinions. Note I've often said lime gold is my favorite.


Slim
 
  • Like
Reactions: cally68

·
Registered
1967 Mustang GT fastback
Joined
·
4,019 Posts
+1 on that. Is the swap doable? Absolutely. Cost efficient? Well that depends upon budget and purpose. There are pro's and con's to doing the 390 swap, the OP will have to decide if the challenges of doing the project (versus staying with the SB) are worth it. FE engines have great curb appeal at shows, enough torque when built properly to tow a semi trailer up Pikes Peak or melt tires/pavement at will, but handling is heavy at the front with significant understeer. Power steering is almost a necessity with an FE unless you have muscles like Arnie has (or had), and the springs, rear end etc. will need changing out, the list goes on...
 

·
Registered
Joined
·
88 Posts
Discussion Starter #18
Hello all,

WOW!

this forum and the experts that sit on it, are FANTASTIC!!!! i am lucky to have found this site ;)

thank YOU ALL for the great feedback.

you have given me a great deal to think about.

i will post back when i have processed all of this info and made a decision.

thank you again,
mark
 

·
Registered
Joined
·
4,987 Posts
I would look into a 351W if you are looking for better performance. It will bolt up to your transmission and engine mounts and will be a lot easier and cheaper to install.
 

·
Registered
Joined
·
784 Posts
Carroll Shelby Removed 390's From His Cars?

Stick with the 289, it is a better engine for the Mustang. The 390 was a truck/boat/"full size" car engine. The 289 is a sports car engine with racing heritage. The first thing Carroll Shelby did with the 390 was remove it from his cars. ' Nuff said.
Be fair, Carroll Shelby removed 390's to put the 390's bigger brother in his cars.
 
1 - 20 of 86 Posts
Status
Not open for further replies.
Top