+1 I'm finding a ton of fox bodies for cheap!

 

I almost went that route in my 65 but I am finding my mpg is not that bad with a properly sized 4100,and my throttle response feels just as crisp as my last fox car.
One issue I have is proper export and Monte Carlo bracing with the normal 5.0 intake, that thing is kind huge and gets in the way of good braces.

 

I used a bar designed my Maler...

 

Simple question with a fairly simple answer... (at least I think so).

If your 351C is a 2V and is properly tuned, it's going to be very nearly as efficient as a 5.0, albeit with the 50 additional cubes and the longer stroke. You're going to get less HP and torque from the 5.0, the additional parasitic loss from the AOD, so it's going to FEEL like you went from a 351 to a 250 six banger.

If the majority of your driving keeps you off the 4 lane divided highway and under 60 mph, you're not going to notice that much more fuel economy by swapping a C4/FMX for an AOD. What you want to do is figure out what speed you will be driving at MOST of the time and target 2,000rpm on the low end and 2,500rpm on the high end at that speed for the best mileage and if that happens under 60 then fine tune it with rear end gearing. If you're gearing needs to be lower to suit your performance needs and you're going to be driving mostly over 60mph, then consider the overdrive trans. There's no reason why you can't put an AOD/4R70W behind a 351C either.

If fuel injection is your gig, then adapt an EEC-IV EFI setup to your Cleveland using TrickFlow's upper and lower intake kit.

 

Simple question with a fairly simple answer... (at least I think so).

If your 351C is a 2V and is properly tuned, it's going to be very nearly as efficient as a 5.0, albeit with the 50 additional cubes and the longer stroke. You're going to get less HP and torque from the 5.0, the additional parasitic loss from the AOD, so it's going to FEEL like you went from a 351 to a 250 six banger.

Do you think the AOD has more parasitic loss than the C4? I'd think they'd be about the same. The C6 is know for it's loss and strength, but I haven't heard about that on the AOD.


Art: I don't have any solid numbers, but if you do mostly stop-n-go driving, you can gear the AOD setup a bit lower than what the C4 was. Check the gearing inside the tranny. I think the C4 has 2.4 vs 2.8 for the AOD (not sure)

Basically it's not just an issue of having one more gear, the gears inside the tranny have a lower 1st, so you can get a taller rear end gear and have the same effect, or leave it and have a quicker/easier 1st.

Lower gears in the tranny make it easier for the engine to get the car moving, lowering the rear end gear helps this as well. Basically if you keep your foot out of it, the engine will have less work to do to move the car.

This usually means higher revs before shifting to get to the same speed, if you can change the shift points back to where the c4 shifted you should be ahead of the game.

Overall the AOD does give you more options for gearing.

Leave it stock if you do a lot of freeway, lower the gears if you do more city.

 

If you are a DIY'er, you can piece together an EFI install pretty economically. The mileage may not be all that much better, but the easy start/run and reliability are big benefits. Check out my website on efi swaps

 

I second this...and strongly recommend reading his website.

If you are patient and crafty, EFI swaps can be done relatively cheaply. Stock explorer GT-40 intakes can be had for $150 in really nice shape and flow 95% as well as $600 aftermarket set ups unless you are trying to spin above 5500 RPM.

I'm doing the swap as much for ease of driving as to maintain something different. EFI set ups are still rare at show and shines in my area. But that's about all I go to...a show and shine with my son to get a burger and some ice cream for 45 minutes and then leave.

Is it worth it? Who knows. I agree that a properly tuned and set up carb can run just as smoothly as an EFI converted engine. But what I like about EFI is that you get to have your cake and eat it too. My engine when done should put around 300-325RWHP but still manage 25+ MPG and fire right up every time and have a smooth idle no matter what the temperature is outside. That's important to me since I drive my car in temps ranging from 35*-100*. Part throttle, WOT, idle...shouldn't matter once I get it dialed in.

Downsides...you need to be brave enough to tackle some simple wiring. The only real big expense can be the fuel pump and fuel tank modifications. But as with everything, that will depend on your route. If you stick close to stock and use the 5.0 ECU, it can be fairly cheap. I'm going with Megasquirt which will add some learning curve and expense.

I've started this swap and it's taking a while, but part of that is I'm doing a lot of "while I'm at its" like fixing an area of rot, cleaning up the engine bay and respraying it, putting in subframe connectors, putting in a hydraulic clutch and power brakes.

But honestly, unless it's all free, don't do it to save money on gas. The money you save on mileage would likely take 30 years to regain if you drive 5-10k miles per year if the swap costs $1000 or more. Its everything else you gain.

 

Bartl, THANK YOU for that VERY detailed explanation. People like you are the reason why I've always loved the VMF.

 

And it's soul purpose will be to be a reliable, fuel efficient (hah, well, as efficient as it can be) daily driver.

So my question is, is the conversion really worth the hassle, money, and time?

Please advise...

How many miles a year is this going to be driven?

 

Just look into a F.A.S.T. FI or PowerJection III system that acts as a carb replacement. That way you can keep the 351C, maintain stock air breather and the carb'ed appearance.

 

A friend of mine is converting a 360 ci powered Galaxy to fuel injection. When he is all said and done it will appear to the untrained eye to still be carbed because he is retaining the factory air cleaner assembly. He is using a Megasquirt system for the computer. For the "carb" I want to say it is some factory GM setup he is adapting to work in his environment, like one of the factor fuel injection attempts from the 80s where it had a couple injectors within what looked like a carb. I am clearly hazy on the details but I do know it is a fairly inexpensive route he is taking and one he has done on other cars. He is going this route simply because he knows how to tune fuel injection but feels a little lost with carbs.

 

I've got a Powerjection III system on my pony - it's basically the intermediate between a carb and a full-blown EFI'd motor. I love it and it's easy to install and nets me 21mpg combined (combined meaning highway at 70-75mph + 'spirited' stoplight driving) on a 289 with Toploader/3.25 rear gears. A full-blown EFI setup and maybe not driving with my foot in it so much would likely get me even better mpg. The Powerjection in itself isn't an economical solution - ran me over $1000 for 3-5mpg gain. It does make the car feel a lot more responsive and quicker, retains the carb'd look, and makes it easier to start and drive anywhere, anytime. Since that's exactly what I was going for, I'm pleased with it. Plus I get to retain all of my other parts and don't have to swap anything else over, which is the problem with swapping completely to an EFI'd 5.0.

I would only go EFI'd 5.0 if you're really going to be driving the car a lot - cost will outweigh the gas you'd save otherwise (unless you find one on the cheap and manage to modify everything else fairly cheaply). If I were you I'd map out the costs of swapping over the engine, project fuel savings, and then calculate how long / how many miles it would take to have the engine pay for itself. My Powerjection unit will take upwards of 6000 miles to pay for itself, which would be easily accomplished by me (road trip to California and back coming up in 2014) but not so much by someone who doesn't drive the car frequently or far. It all depends on how much you drive!

Of course, if you just really want an EFI'd 5.0, might as well

 

My point about the bracing still stands. You can make a simple helm joint tube setup, even a welded round rod setup, but that is missing one plane of strength. Imagine if you were holding the ends that mount to the shock towers and I was holding the end that mounts to the firewall, could you twist the ends and make one of them higher than the other? If you can twist it, it's missing one important task, the export brace is not only designed to prevent the towers from leaning back, but it is also to prevent the shock towers from twisting in relation to each other under load, that's why the originals were thick and wide and flat, to provide torsinial rigidity.

Is it a huge deal, not really I guess, but it seems like a neglected fact. Do you really think ford did not have any round stock or tuning laying around to make those braces?

With that said I would not let it stop me from going efi.

 

From my basic understanding of car geometry (I do structural engineering work) is that the export brace is there more to keep the shock towers from moving in relation to the plane of the shock towers (ie, they won't move closer and further apart) while driving. Problem is, you obviously can't put a brace across the top else the engine won't fit in. So, the next logical method is to route the stress around the engine, which would require the brace. Round stock is stronger, but stamped flat steel is cheaper. It's not a complicated stamp and as stamped metal, it's a heck of a lot easier to trim if any adjustments need to be made.

The fender walls tied to the subframes is what keeps the towers from moving fore and aft. Because they are tall, they can be made thin to provide the required support.

Vertical motion is resisted by the subframe and the roof (for those of you that have it) via the same inner fenders. The original braces are on their weak axis in the vertical motion plane.

End of the day, the braces are more there to provide dimensional stability athwartships (side to side) for the shock towers. However, when you look at the bracing, their original design provides some support, but isn't that great. It was made wide to help provide better resistance to bending in the plane created by the stock tower tops but still isn't great. Welded round stock would have been far better.

Now, I do agree, just replacing the stock brace with only a helm joint version of the brace alone is not doing you any favors and I do agree, it is not replicating the original intent of the brace. But its the movement towards one another the brace is trying to prevent. Again, a helm joint version of the original brace alone will not prevent this at all. You really do need one with the brace across the front of the engine (monte carlo brace) and then preferably, tie them all together (like TCP, or my home made version). Now granted, that still won't resist motion of the shock towers in the vertical plane (but that was addressed above), but it will keep them from moving in the other two planes (towards either other, and fore/aft). But if you look at any modern sports car, especially the european ones, their shock tower braces usually run right over the engine and just connect the two shock tower tops together (okay, strut towers).

So I guess, my long winded answer agrees with you, but I would argue the original brace isn't adequate either. Either way, replacing the original with just a helm joint version with no monte carlo bar variant, I do agree with you, is a poor idea. But we have tons of anecdotal evidence for that statement already.

I love my brace kit. Was easy to make and relatively cheap. Once I got it set up, the front end of my car got remarkably quiet and stiff.

Also, don't assume that because Ford could do something, that they would do it if another method saved them $.10 per car. Trust me...been down that path on my explorer where ford used plastic washers for the automatic hubs to save $1 per car. My options there were to either buy new ones ($400) or rebuild them and replace them with a proper metal washer. I obviously choose the later and cursed ford the entire time.

 

I dont want to sound argumentative, but the brace did more than what you propose. It did help reduce towers from moving in and out, and back and forth but it also makes a difference in the shock towers from moving up and down in a different plane, it reduces twist, to what degree is to be determined. But it does make a difference. Try to twist the good one, its kinda stiff.

After all, the original bolt in braces from ford could prevent the towers from leaning back, I would go so far as to bet they worked as well as a tube in that one plane. But you are right in that the OE setup did nothing to prevent the towers from wanting to touch under load or compression.

Modern euro cars re not even close to the flexi flyer that was the vintage mustang, so we will just move on, they are filling the void in strength left by the engine hole, other deflections are handled by better stampings and overall design.

And ford was aware of and even used round tube for bracing, they could have built and installed what many today consider to be a brace. The ragtop cars used some tube, but in the end the exported cars needed more than a simple tube setup could offer.

I dont want to harp on this or sound obsessive, I mean these are street cars that rarely see the need for much of what we install but I am constantly seeing these goofy multi-heim jointed braces at shows and on-line and it seems odd that people dont understand the difference between strength and fashion. The real killer is the guy at the show with the 5.0 motor and no braces whatsoever with stock suspension, thats just lazy.

If I were doing the 5.0 with the OE type intake I would use the Maier triangular one piece because it uses a triangulation for added strength.


Also, are you certain that those plastic washers had no reason for being?

I worked in automotive manufacturing for several years dealing with engineers and prints and I can tell you, little happens without reason.

 

FWIW, I used to run a slightly modified 351W in my '69 Cougar daily driver. I bored it .030 over, turned the crank and installed an Edelbrock Performer cam, intake and carb. My original distributor was shot so I replaced it with a Mallory Unilite.

That Cougar ran and drove amazingly well. On even the coldest of mornings, I would tap the gas pedal once, bump the starter and "VAROOM!" it roared to life. The fast idle would stay on for a short while, then the electric choke would slowly back off for warm-running operation.

The trans in my Cougar was an FMX. The rear gear was probably a 3.0, or something similar. And my MPG was pretty darn good for a 351.

I bought a calibration kit for the carb and got it dialed in really well. The only issue I had with that engine was it originally had dished pistons and closed chamber heads for a 9:1 compression ratio. I installed flattop pistons. I don't know what the resulting SCR was, but it must have been well north of 10.5:1 because I had to back off the adjustable vacuum advance to keep it from pinging. And I always ran premium fuel. I lived six feet above sea level at the time, so that didn't help the compression issue. Of course, the Performer cam was pretty mild and didn't reduce compression at low RPMs at all.

I drove that Cougar daily for twelve years. Unfortunately, the body rusted out beneath me from the nonstop rain and salt on the East Coast roads. When I sold the car, the engine still ran flawlessly.

Anyway, I think if the OP built the 351W he currently has, it would run great in that big pony. And I think a classic carbed engine would be more reliable than an EFI pulled from a junker.

 

My 68 has a 5.0 EFI, AOD tranny and 8.8 rear-end, (I don't know the ratio) out of a 91 Lincoln and it gets about 22 MPG on the hwy. Stock injectors and throttle body. It has an Edlebrock 5.0 Performer Intake and an E-303 Cam.

 

Some years ago a 1982 F100 was my motorcycle hauler. It had a transplanted (stock) 351W from a Crown Victoria with the original 2 barrel VV carb. Also the AOD. LWB with a 9 inch rear. Only real mods were long tube headers and dual exhaust. On long haul freeway 1000 mile trips carrying a 400 pound bike I consistently got 21mpg. Replacement '87 F150 was an EFI 4.9 with the lighter 5 speed manual transmission and 8.8 rear. Exact same trip got 17mpg. EFI, smaller displacement engine, and a manual transmission, color me unimpressed. Got rid of that truck. The F100 died but its engine lives on. Rebuilt, warmed up, and in my '67. With a 4 barrel carb. The old VV is on the shelf.
SWMBO's driver for years was a 5.0 Mustang with an Edelbrock 4bbl. Driven daily all year round we failed to notice the "unreliabilty" and starting troubles of being carbureted.
SWMBO's car required the throttle to be floored once to set the choke and the throttle not touched when it was hot. The only troubles it had starting was when whoever was driving was used to EFI, not a "Car person", and ignored my starting instructions. (Daughters)
My latest F150 is a 5.0 I upgraded to a 5.8. kept the EFI and have no intention of changing it even though I suspect it won't reach that 21mpg the old one could. It works very well and doesn't confuse the idiots who need to borrow it from time to time.
Go whichever way really suits your purposes and most importantly, is what you want.

 

I went with EFI on my '65.

It's great and everything, but I don't think it's "economical" in the sense that I spent a lot of money on an EFI intake, fuel rails, fuel injectors, a custom wiring harness, an ECU, fabricated an intake system with a Lincoln MAF, PLUS had to install a return style high pressure fuel pump, and ended up with a TweecerRT programmer to handle the tuning. It was thousands of dollars for a car that gets driven 2000 miles a year.

That being said, I like everything about it. Instant start up and drive. No choke to mess with. Complete elimination of vapor lock (which I had a big problem with).

The reason mine was a bit more involved was it went on a 347 which meant I couldn't just swap over stock 5.0 parts.

Oh...and when you get done, your car won't be worth 1 dime more than it is now.

The reason I did it was it was a fun challenge and I learned a lot. If that's what you want, then have at it. Otherwise, spend the money on the engine and not the EFI system. You can always do the EFI system later if you want to.

Phil