What Powertrain for My 73 Mustang Convertible?

[Don C]

I agree completely with Geoff. It's not only the engine setting under the hood, but it's also the sound. Nothing like a V8. No matter what you do to a 4 cylinder it still sounds like a 4 cylinder, unless you keep it wound up to 8,000 rpm, then you can make it sound like an old Indy car.

 

[giantpune]

Late to the party again, but reading this, I just had to add my thoughts.
To start, I try to always say, "your car, your way", but to be honest, if I saw a 71-73 Mustang at a show with anything less than a Coyote engine swap, I'd be disappointed.

The way I see it, any time you swap to a newer generation of motor, its only cool while its the newest generation.

Back in the 80s and early 90s, people were swapping in the pushrod 302s with the EFI and serpentine belts out of the foxbody and on up to the 1995 mustangs. Then when ford came out with the 4.6L mustangs in 96, people started putting those into their classic cars, and it was acceptible. now that ford has rolled out the coyote, those older 302H.O. EFI and 4.6 swapped builds get more frowns. The same will happen to the classic cars with coyotes in them when ford makes whatever the next generation of motors is. The coyote swap requires a bunch of non-trivial modifications to our cars. I'm willing to bet there are some folks doing them now that will regret it when the next generation of motors rolls out.

I think if somebody cares at all what other people think about their car, or they care about the resale value, its better to stay with something that is compatible with the original motors.


As far as the horsepower vs fuel economy discussion goes, thats why they invented boost. Slap a vortec/procharger/turbo on whatever motor makes you happy. Thats the "boost" in "ecoboost".

 

[Bobby]

If I still had my 78 Mustang II, I might be interested in a 2.3L turbo engine. Wouldn't dream of putting an ecobooooost engine in my 72. Thats an abomination! Same with an electric motor with tape recorded vrooom, vrooom!

 

[73StangJK]

Late to the party again, but reading this, I just had to add my thoughts.
To start, I try to always say, "your car, your way", but to be honest, if I saw a 71-73 Mustang at a show with anything less than a Coyote engine swap, I'd be disappointed. A 2 ltr Ecoboost would just look wrong. I mean there is this huge engine bay (until you shoe-horn a Coyote in there), with a relatively tiny motor dropped in. Yeah not for me!
Here in Canada, well Ontario, I'll currently be paying $7.60 Cdn for 3.8 liters or 1 US gallon of premium gas. With the milage I get from my 351C 4V M code, it will work out to be about 50 cents per mile. Yes it chokes me up to pay that much, but I really don't care. The car is a blast to drive and I can get between 12-16 mph /US gallon, 15-20 imperial.
So I'll spend an extra 200 bucks on gas for the summer's fun, still beats all the agro of an engine swap, just to save 50 cents.
If it came to needing to get better mileage, better gearing would be my go to approach, like a 6 speed manual. I already have 3.25:1 rear gears.

Yeah, a lot of Mustang guys think a real Mustang has to have a V8.

My brother had a Buick GN and that thing was terrifying. It didn't handle as well as my Stang but in a straight line there was no beating that turbo charged V6.

But, I get you. I'd hoped at this point in my life to not have to care at all about the piece of gas but I still haven't hit that loto jackpot.

 

[Stanglover]

Yeah, a lot of Mustang guys think a real Mustang has to have a V8.

My brother had a Buick GN and that thing was terrifying. It didn't handle as well as my Stang but in a straight line there was no beating that turbo charged V6.

But, I get you. I'd hoped at this point in my life to not have to care at all about the piece of gas but I still haven't hit that loto jackpot.

I get you too. It's mind blowing the power that manufacturers are getting out of smaller displacement engines these days, let alone the mighty V8's like the Coyote or Chrysler Hemi Hellcat. My VW Passat with a 1.8 ltr turbo 4 banger will easily out run my Mustang on acceleration.

 

[IA Rider]

I think the 2.0 ecoboost would be an interesting and awesome swap. Do your research if you decide to go this way. I made the decision to go with a 7.3 godzilla in my 73 mach 1 project. I am finding the aftermarket is starting to offer some swap solutions but the prices are very high and will remain that way until companies like Holley and Edelbrock get more products to market. These are our cars to build however we desire so build it your way and enjoy it.

 

[Greg]

I prefer them the way ford made them 6cyl. and all. Maybe some vintage performance stuff at most. One of my favorites is the elusive factory 64-66 6cyl. 4sp. . I own a factory 84 Turbo Gt as a standard 4cy. car doesn't really do it for me. If I want a 71-73 performance V8 I stick to a M, Q , R ,J and C code and don't buy anything else. I don't need more power than a Factory H code 351 V8 2bbl. ever.

 

[Lazarus]

Lazarus,

I appreciate and concur with your philosophy. These incredible cars are meant to bring joy in whatever form their caretaker envisions.

Off the subject, your convertible is stunning! Looks to be a beautiful restoration and I would love to see more images of what you have created. I am in the middle of a restoration/modification of a '73 convertible and appreciate seeing other finely crafted cars for inspiration. Enjoy!

Thanks very much for the compliment brother! I myself was inspired by @luxstang. Though I guess our cars don’t look too much alike I just really dug his car and it motivated me to make my 72 vert with a musclecar vibe. It ended up a hodgepodge with the boss hood and tail-panel blackout, along with some hints of younger Mustangs (the wheels are later Bullitt rims, and the paint is Magnetic Metallic from recent Mustangs). I think it turned out pretty cool.

The car’s progress has sorta frozen during the pandemic, as I was very busy with work the last two years. It needs interior work and although the engine is pretty good I also purchased a 70 4V to rebuild and swap in. Hoping to work on it more this summer.

 

[73StangJK]

I agree completely with Geoff. It's not only the engine setting under the hood, but it's also the sound. Nothing like a V8. No matter what you do to a 4 cylinder it still sounds like a 4 cylinder, unless you keep it wound up to 8,000 rpm, then you can make it sound like an old Indy car.

*Throws together a loud-a sound system and plays V8 Sounds of Nascar in 4 cylinder powered Mustang*

I mean yeah the sound of a roaring V8 make me just happy, but does it make me as happy as actually just driving the Stang listening to...

 

[73StangJK]

Thanks very much for the compliment brother! I myself was inspired by @luxstang. Though I guess our cars don’t look too much alike I just really dug his car and it motivated me to make my 72 vert with a musclecar vibe. It ended up a hodgepodge with the boss hood and tail-panel blackout, along with some hints of younger Mustangs (the wheels are later Bullitt rims, and the paint is Magnetic Metallic from recent Mustangs). I think it turned out pretty cool.

The car’s progress has sorta frozen during the pandemic, as I was very busy with work the last two years. It needs interior work and although the engine is pretty good I also purchased a 70 4V to rebuild and swap in. Hoping to work on it more this summer.

You all need to move to Lubbock Texas. I could take apart and put a 71-73 Mustang back together in my sleep. It's like I've been there done that and this too. My brothers grew up and I had kids and the Mustang has been sitting for about 5 years now with gas I need to drain out of it. lol

But, I still do go out and stare at it from time to time and move stuff off it so I can see it better. I listen to my favorite songs and they are just not as good as when I'm playing them while sitting in my Stang.