74 carrera engine swap?

[ssfrancis]

Long time lurker first real post…. Love this forum, amazing body of information.

Yes… this is another 3.2 or 3.6 swap thread. Sorry for that but I’m looking for some input.
A couple years ago I bought a 1974 US Carrera. Original engine and gearbox, but missing some important parts like the ducktail and steering wheel. I drive the car almost every day and love it but I’d like some more power. The 2.7 was rebuilt and has most of the goodies, runs great, but lacks the uumph. The gear box was also rebuilt.
My father (who gave me the 911 bug early in life) still has an 88 Carrera and it pulls much much better although I like driving the 74 more due to the lightness and it just feels more raw.
My intended use is really a street car, but a few track days a year aren’t uncommon.

So here are my options with a regular guys budget = me doing all the work:
Option 1 - Should I swap a 3.2 and keep the original gearbox 7.31 r/p, put the 2.7 on a pallet and save it for originality. (mag case 7.31 up to the job?)

Option2: Buy a 3.6 and a later 915 (maybe LSD?) and sell the 2.7 and gearbox.

The other issue is that I really like the long hoods… so I could conceivably see a backdate in my future. My car has the RS flares and would be cool as a longhood.

I guess this all hinges on value of keeping a US Carrera original. vs doing what I want to do with the car. Thoughts?

Any and all input appreciated!

[JeremyD]

Option 2 - and keep the 2.7 and original 7.31 gearbox - especially if it's a real carrera (even a US one)

OR

Sell your car - and buy someone else's 3.6 conversion/track toy and be miles ahead.

Buy a 3.2 carrera and make it as light as possible with all the suspension goodies

[Dodge Man]

Since you have a rebuilt gear box, have you taken a look at a rebuilt 3.0 and keeping the CIS? The 7:31 will hold a 180HP US 3.0 well with normal driving & occasional red light GPs. Mine was "N-I-Z-E" nice with the 915 7:31. If you go for an 84-86 3.2 try to get the matching trans & ECU box too. IMHO Just keep your numbers motor & trans for vehicle resale value. A steering wheel & tail can be replaced to keep as much OEM as possible. Make your self happy and keep the restoration parts for the years down the road when the OEM resale value comes around.

[Lapkritis]

^x2... never break up a matching set.

[manbridge 74]

Option 3: Convert 2.7 to MFI with RS spec cams and PCs while driving car with 3.2 or 3.6 that you'd sell off after you are done with conversion.

[ssfrancis]

Thanks for the input guys.
My gut tells me keeping it together is the right thing to do.

Re: Option 3- Now we're talking!
Building an RS spec motor takes a lot of parts sourcing, but would be a great project if there was no rush.

[Roger 911]

I have a '72 T that I've owned since '98. Last winter I swapped in a '84 3.2 with matching 915 LSD. I love it. It is more fun on the street and the track. I think this is possibly the best "bang for your buck" (especially if you sell off your existing drive train). On the other hand, if your concerned about originality and/or resale, and you have a bigger budget, building the 2.7 into a RS spec motor and beefing up the mag 915 would be a good route too.

Most importantly, figure out what is most important to you, and make yourself happy.

Roger

[timmy2]

Is it an ultra rare, low mileage, pristine example that will be worth hundreds of thousands soon?
If the answer is no, do what you want to do with the car.
You only live once....

[fintstone]

Originally Posted by JeremyD

Option 2 - and keep the 2.7 and original 7.31 gearbox - especially if it's a real carrera (even a US one)

OR

Sell your car - and buy someone else's 3.6 conversion/track toy and be miles ahead.

Buy a 3.2 carrera and make it as light as possible with all the suspension goodies

^^^^this^^^^

You would have no problem finding a home for a '74 Carrera. Or buy a nonmatching, not original car to hotrod.

or install a hotrod 3.0 with your 7.31. it will require the least changes to your car and all are easily reversible, it will look and feel similar to your 2.7 but will be quicker (will outpull a later Carrera like your father's due to weight and gearing yet still retain the raw feeling) and store your 2.7 to reinstall later if the urge strikes you.

[yel911]

IMO, keep it original. You can always find the parts you need to put it back to stock. ($$$)

[manbridge 74]

And post a pic or two? (Of said automechanical conveyance.)

Welcomes to you as well...

[will hung]

If a hot rod engine is what is important to you, I recommend selling the car; and trying to find a non original SC. Then you can go to town with the drivetrain.

If that is not an option, I recommend, like others above, that you swap in a hopped up 3.0 that maintains CIS. I say this because you can minimize wiring modifications that might not be reversible.

[O' yeah"74]

Is it an ultra rare, low mileage, pristine example that will be worth hundreds of thousands soon?

If the answer is no, do what you want to do with the car.

You only live once....

So what do you all really think the value is now or will be in a year or two on a "pristine" original? I have a '74 911 2.7 (rebuilt at Aase motors), original signal orange and very nice interior. I too have thought about a 3.2 swap and I also have the same questions and concerns.

So again, what's a realistic value on these cars in excellent original condition in today's market?
What about in 5 years?

[javadog]

Hard to say what the value of your car would be. No real details...

That said, the value is going up and I don't see it ever going the other way. A '74, even if not a Carrera, is the most valuable of all of the mid-year cars and if you want a bigger motor you should sell the car you have, buy an SC or a hot-rodded mid-year and pocket the difference in cash. Every day there are fewer nice, original cars. They will increasingly be sought-after.

Swapping a 3.2 into your car will only cost you money, now and later.

As for the original question, no way would I consider swapping an engine into an original Carrera.

JR

[O' yeah"74]

Thanks JR, that's what I assumed. I'll keep mine the way it is and save up for track toy someday : )

I know the prices are going up on the mid years as of late.
Let's just say everything that needs to be done to this motor has been done plus some. I've been too lazy to list all the engine/mechanical upgrades. The paint is original and beautiful, interior as well, sitting on 16" Fuchs.

[Roger 911]

Originally Posted by O' yeah"74

Let's just say everything that needs to be done to this motor has been done plus some.

Given this, it would seem a bit unnecessary to consider replacing it...but a 3.2 in an early car is a blast

Have fun!

Roger

[E Sully]

I had swapped an '86 3.2 engine and transmission into my 1973 cis. My goal was to be able to easily restore it to original, it's a matching numbers long hood. It was great having the torque and smoothness of the later engine. It is important to have the later transmission for this conversion, since using the original would require cutting the housing for the flywheel sensors. Not easily reversed.
I am currently restoring the original, and the biggest part is welding in a small round patch below the rear seat that was cut for the dme harness.
I paid $5,500 for the '85 engine, harness, and transmission. It had worn valve guides at about 68,000 miles so I put another $3-4000. Into new guides, valves, and rings. I built my own rear electrical console for the conversion. It started easily and ran great till I recently decided it was time to restore the original engine and transmission. I sold the refreshed top end 3.2 for about $7,000 and still have the '86 transmission. Overall, it cost me a couple thousand dollars for the 5 years I drove the car with the 3.2. Not too bad a price in my opinion. Cost will of course depend on who does the work and ability to find a later engine at a good price.

[O' yeah"74]

Thanks for the info E Sully. Just out of curiosity why are you switching back?...... Selling?... Or something else.

[E Sully]

When I bought the car back in 1987, it was to have fun with. The cars were cheap, and I always enjoyed building engines, and road raced motorcycles. I ran it stock at first, then slightly modified with Weber carbs, then the 3.2. Now, the cars value, my age and health have something to do with it. I have worked in construction for 33 years, I just had a hip replacement. With the value of a numbers matching '73 cis I figure it's time to restore it before I don't feel up to crawling under a car anymore. Selling is not really on my mind. It's just that as I get older I find I can enjoy the car stock, and don't need the modifications anymore to enjoy driving it.

[ssfrancis]

My Carrera is in nice shape but not pristine. It has about 140k on the clock, original leather (in amazing shape), original 15in fuchs and an original 75 Carrera tail (no duck). It is missing some of the interior bits, but as was said they are replaceable. It’s a original CA car with some history from Vasek Polak, which is cool.

What I ‘m hearing is that it would not only be a shame to break up a # matching US Carrera, it also might be an unwise choice in terms of value…. But is a 140k US Carrera ever going to be worth more than $50k? if so I’ll sell it for 45 right now ☺

I guess I just have to weigh that with enjoying the car the way I want too.
I love working on cars, so not modifying is difficult for me not to do. I do all the work, except machining, myself so that saves on cost.

It also sounds like if I do an engine swap (except 3.0), I should do the tranny also which affects the cost. I don’t think it would be worth it for a 3.0.

Pic attached and thanks for the welcome!