Engine Efi 351w Swap

nelzfoxes

5 Year Member
Aug 20, 2013
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Alright. I am just trying to plan ahead. Who amongst us has successfully completed this swap? Chime in with any problems you ran into or parts you had to buy, etc. I ask because this is the next step for the Daddywagon. I just about completed the installation of an efi 302 from a 1986 mustang gt into a 1985 Ford LTD foxbody station wagon. I used Ford's M-12071-A50 harness. The computer is A9L. The meter is Pro Flow(?) calibrated to 24lb injectors. The car starts and runs. Now that I am so close to driving it the time has come to build and install a 351. Thoughts?
 
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Almost exactly a year later... I have been driving the daddywagon with a 351 for a couple of months now. I still have a lot more to do but driving this car is a lot of fun. I highly recommend a 351w efi swap. It’s probably cheaper than a coyote swap and less labor intensive to accomplish.
 
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This will be my Stangnet Daddywagon thread. Latest, has the daddywagon needing a different mount setup for front wheels. Up until now I was running 25mm wheel spacers up front which bolt to hub face and have studs pressed into the spacers which mount the wheel. This was necessary because of the deep backspacing of crown vic steelies and clearance for cobra brakes. Studs are failing on both sides. I am going to reduce the spacer width to 1/2 inch and use longer studs.
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The daddywagon needs a starter and possibly complete flywheel and clutch assembly. But funds are low so I only bought the starter to see if I can get away with only a starter change.
 
There are no reverse lenses on the wagon because they fell off a long time ago. But I found a craigslist ad from Canada and sent a postal international money order to Canada to buy someone’s stash of three reverse lenses! Thanks Doug!
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This will be my Stangnet Daddywagon thread. Latest, has the daddywagon needing a different mount setup for front wheels. Up until now I was running 25mm wheel spacers up front which bolt to hub face and have studs pressed into the spacers which mount the wheel. This was necessary because of the deep backspacing of crown vic steelies and clearance for cobra brakes. Studs are failing on both sides. I am going to reduce the spacer width to 1/2 inch and use longer studs.
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Apparently the other thread I started ended up being the Daddywagon thread... or maybe both are?
 
At the heart of the Daddywagon is the efi 351w swap. I’ve gone over this before but it needs to be said (again) that this swap is what you foxbody guys and gals are looking for. Especially if your intention is to drive on the street. If you’re building more of a race car then that’s different. Some of us have it in us to do both. If you have an efi fox and would like a dedicated street cruiser that sounds great and runs good all over the place then do exactly as I did only do it cleaner. I think a little bump in compression with a bit more power and perfection! A street car lives between 1000 - 3000 rpms. Once in a while you do a pull. Like on the way home today on the turnpike. Sitting in overdrive I decided to do a pull, bang a downshift then spin it to maybe 4500, back into overdrive and let it pull to over 4000 in overdrive. I’m well over a buck. I can hang with 95%. The best I’ve seen on video for a street car was this:

View: https://youtu.be/SfMC9Egd1F8

I’m not quite there yet. But as close to that with a smooth idle, naturally aspirated I’m thinking.
 
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Here is a list of the engine parts on my car right now:
1. F4TE block engine out of a 1994 Ford lightning
2. GT40 cast iron cylinder heads
3. 1.70 : 1 cobra roller rockers
4. Stock H.O. camshaft from a foxbody mustang
5. Accufab 75mm spacer and throttle body
6. 75mm MAF calibrated to 24lb injectors
7 . 24lb injectors

I have another engine build planned. I might try to get output numbers for the engine that’s in the car for comparison purposes.
 
I am building a 393w right now, you are going to leave alot behind running those heads and cam. The 351 wants air to breath and a factory cam for a 302 is downright tiny in a 351.
You can retain stock idle and drivability by running a cam with a wider lobe separation angle, a 110-112 will be choppier than a 114.
 
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I am building a 393w right now, you are going to leave alot behind running those heads and cam. The 351 wants air to breath and a factory cam for a 302 is downright tiny in a 351.
You can retain stock idle and drivability by running a cam with a wider lobe separation angle, a 110-112 will be choppier than a 114.
If there is more to be had, great! I think a bump in compression and aluminum heads. But the camshaft I feel is matched to the computer. I put the cobra roller rockers in there to compensate for the larger displacement. There is also the fact that I am having so much fun driving it! I don’t doubt that there is more power, but with non-variable valve timing everything is a trade-off. Then you have to tune and you get your “number” on the dyno but as you drive it to the convenience store you have to keep your foot on the throttle a little to keep it running at the light. I beat the crap out of this car and on the street that means shifting around 4k. On the highway I can turn most in to little dots in my mirror. I am preaching... I know, but it’s because I just drive this car. I don’t have oil pressure or coolant temp gauges and the engine light is always on because TAB and TAD solenoids are gone but I drive it 30 miles each way to work 3 - 4 times a week. In NJ they pump your gas and I tell the guy or gal to fill it up regular unleaded. Add to that my car isn’t 100%! The air conditioning isn’t hooked up, there is an audible header leak, etc. Yes there is no replacement for displacement, and your 393 is gonna punish my 351, but you’re not gonna have MORE fun than I’m having driving this car on the street! You’ll have more fun than me at the dragstrip... and I’m fine with that.
 
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My car will likely also get the same fuel milage as well.... you can get a more aggressive cam without loosing drivablility my 302 has a MUCH larger cam and with the 114 LSA it idles and drives like stock.
Alright. I’ll have to take your word for it. I will look in to your build and others. That is exactly what I want, and have. Idles and drives like stock!
 
I drove it work today. It was cold in the morning and the car hauled a#*! Coming home in 80* heat I beat the crap out of it again to keep up with what I believe was an evo and a pickup also. We were all weaving in and out of traffic. Nothing too crazy and I was able to keep pace. The engine isn’t over heating at all. I think with the engine being the low compression variety, the stock radiator and the stock clutch fan are sufficient.
 
I am pulling the tan dash and console from a 1989 mustang. Well the parts car was a 2.3 4cyl. car. It has occurred to me that the 4 cylinder mustang fuel lines would be ideal for a lightning efi 351w swap. This is because the lightning fuel rails connect at the driver’s side rear of the engine just like the lowly 4 cylinder fox lx mustang! I might try this for a cleaner installation.
 
I am pretty sure diameters are the same. They must cross over at some point under there. I brought them up because I messed up when I lengthened v8 foxbody fuel lines for the Daddywagon. I cut the fuel lines in the wrong spot.
 
The fuel lines make a turn from the side of the car along the doors to the driveshaft tunnel. Because I lengthened the lines along the doors the turn to the driveshaft tunnel ended up being in the qrong spot. For those of you lengthening mustang lines for a longer wheelbase fox body make your cuts in the tunnel section.