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1973 Mustang v8 swap
#1
I have a 1973 mustang fastback base model with the 6 cylinder 250 engine, and a 3 speed manual. I want to do a v8 swap and was hoping for some info on what I'm going to run into during this swap. It has the 5 lug drivetrain, so I hear it should be a bolt in swap. I have a wrecked 72 coupe with a 302, so I think have everything I need? Will the trans bolt right up to the 302? Will the clutch handle it? Does the input shaft need changed? Any info you have let me hear it!
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#2
Hi 48, and welcome!

I can't be any help on the swap, but am interested in the 250 when you are done with it.

Good luck on your project.
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#3
You'll need the frame brackets and insulators from the '72. The trans, bellhousing, block plate, starter and all the clutch gear will work on the 302, except the flywheel. IIRC the 250 has a 157 tooth flywheel, so you'll need to get one with the same tooth count to fit in the bellhousing, which was used on the pre-71 302 cars.

https://www.rockauto.com/en/moreinfo.php...7&jsn=3929

I'd get a new clutch kit, never had much luck with re-using used clutches. The 157th flywheel fits a 10" Long style clutch.

https://www.rockauto.com/en/moreinfo.php...7&jsn=3942

Everything else is a direct swap. Use the throttle cable from the '72, you might need to use the gas pedal as well. The 250 cable is way too long. Move the cooling system from the 72 to the '73. You may need to rebuild the Z-bar with new bushings. Any Mustang shop will have the parts.Use the engine harness from the '72, it probably will plug right into the 73 engine compartment harness, otherwise repops are available. If the 302 car has factory tach and gauges, you will have to swap the senders to the correct ones for the warning lights in the '73.


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#4
(07-22-2019, 05:54 PM)Horsin\ Around Wrote: Hi 48, and welcome!

I can't  be any help on the swap, but am interested in the 250 when you are done with it.

Good luck on your project.
Horsin around... ever get to Ohio, there is a 250 here
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#5
The under hood wire harness from a 72 will not swap over to the 73. Lights up front are different. Will take some work but can be done. Midlife is the best source.
I also believe the front coil springs are of a different rate not sure with just a 302. Sway bar might also be different. The rear will have the smaller u joints also. 
All 71 - 73 mustangs had 5 bolt wheels.


When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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#6
(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: The under hood wire harness from a 72 will not swap over to the 73. Lights up front are different. Will take some work but can be done. Midlife is the best source.

I am referring to the engine gauge harness plugging into the engine compartment main harness.


(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: I also believe the front coil springs are of a different rate not sure with just a 302.

There are a couple applications that the 250 and 302 share the same spring. 302 weighs a bit more, probably won't make any real difference.


(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: Sway bar might also be different. The rear will have the smaller u joints also. All 71 - 73 mustangs had 5 bolt wheels.

250 and 302 use the same driveshaft and u-joints 71-73, for both the C-4 and the 3 speed manual. Sway bar is the same base 3/4" diameter unit. 8" rear bits are the same.


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#7
runninpony 
(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: The under hood wire harness from a 72 will not swap over to the 73. Lights up front are different. Will take some work but can be done. Midlife is the best source.
I also believe the front coil springs are of a different rate not sure with just a 302. Sway bar might also be different. The rear will have the smaller u joints also. 
All 71 - 73 mustangs had 5 bolt wheels.
Whaddaya mean just a 302 ?  Angry

71-73 Mustangs never die, they just go faster!
[+] 1 user Likes NOT A T5's post
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#8
(07-23-2019, 11:54 AM)Hemikiller Wrote:
(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: The under hood wire harness from a 72 will not swap over to the 73. Lights up front are different. Will take some work but can be done. Midlife is the best source.

I am referring to the engine gauge harness plugging into the engine compartment main harness.


(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: I also believe the front coil springs are of a different rate not sure with just a 302.

There are a couple applications that the 250 and 302 share the same spring. 302 weighs a bit more, probably won't make any real difference.


(07-23-2019, 09:10 AM)Carolina_Mountain_Mustangs Wrote: Sway bar might also be different. The rear will have the smaller u joints also. All 71 - 73 mustangs had 5 bolt wheels.

250 and 302 use the same driveshaft and u-joints 71-73, for both the C-4 and the 3 speed manual. Sway bar is the same base 3/4" diameter unit. 8" rear bits are the same.

The 250 6 weighs 385 lbs., and the 289-302 weighs 460 lbs. A difference of 75 pounds
Ford 289/302 V8         460         (late 5.0s are a bit lighter)
Ford 170-250 L6         385         (except Australian w/aluminum head)
Ford 351 Cleveland    550         (includes BOSS and Australian 302-C)
http://www.gomog.com/allmorgan/enginewei...ights.html[/url]
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#9
NOT A T5 Wrote:
Carolina_Mountain_Mustangs Wrote:The under hood wire harness from a 72 will not swap over to the 73. Lights up front are different. Will take some work but can be done. Midlife is the best source.
I also believe the front coil springs are of a different rate not sure with just a 302. Sway bar might also be different. The rear will have the smaller u joints also. 
All 71 - 73 mustangs had 5 bolt wheels.
Whaddaya mean just a 302 ?  Angry
He was referring to the weight of the engine. Calm down.

73 Grandé H Code. Headman long tube headers, T-5 Transmission, 3.70 Traclok, Lowered 1" all around, Aussie 2v heads w/ 2.19 intake, 1.71 exhaust, screw in studs, full roller cam 608/612 lift 280/281 duration LSA 112, Quick Fuel 750 CFM double pumper, AirGap intake.

- Jason


[Image: 082-hot-rod-power-tour-2017-1970-1970s.jpg]
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#10
runninpony 
I am calm Jason, I think we're all on here for the love of 71/72/73 Mustangs no matter the engine, transmission etc.

71-73 Mustangs never die, they just go faster!
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