Well guys im doing it. Had an opportunity to get a good low mileage 351W for free from a friend, and its going to replace the worn out 302 in my F150. The new engine is from 85, What Im going to do is put a FI intake manifold on it, and use all the computer parts from my 302, turning this one into a MAF 351. Got a couple questions first though:

-With MAF, is there no MAP sensor? I know on my SD 351 its mounted on the firewall by the HVAC, but on my 302 theres nothing there....?

-Do 302s use an intake air temp sensor? Theres a threaded hole in the lower 351 intake into one of the air runners, but my 302 has nothing there....?

-I think im going to have to block off the EGR, Im going with shorty headers on the 351, and the piping from the 302 wont work. Thoughts?

-Would it be a bad idea to remove the connection between the PCV valve and the upper intake? I dont like how it oils up the intake, eventually turning everything in there to carbon....

-Will the rest of the 302 emissions work on the 351? I dont live in an emissions testing area, but i dont like the idea of taking everything off on my DD.

Thanks for any help, if you need more info ask and ill provide what I know!

 

MAF trucks don't have a MAP, but strangely enough MAF mustangs from this era did, so it depends what engine computer you are using.

Early 5.0s were the same as the 5.8 with an intake mounted air temp sensor, but I believe the sensor was moved to the airbox around the same time as when MAF was introduced, so if you're using the truck EFI setup with the airbox mounted sensor you don't need another one mounted in the intake so you can just plug the hole.

Well actually the 5.0 EGR tube will work if you mount a fitting for it on the top of one of the header runners, but you could also disable the system or remove it completely... though that will cause codes.

The oil mist that gets pushed out through this valve has to go somewhere, so it's either into the intake or all over your driveway.

What "emissions" are you referring to, the air injection? This system will transfer to the 5.8 if you get a 5.8 specific crossover tube for the back of the motor, but the whole works of it can be deleted without affecting engine operation too.

With all that addresses, is the donor motor a 4bbl or 2bbl? if it's a 2bbl you're gonna want to change the cam, and you don't need to limit yourself to SD friendly grinds with MAF.

 

My EGR tube heads under the upper intake, dunno where it actually connects to the exhaust system. Its not into the headers or ypipe....

Ok, I think ill just let it vent then. Oil mist doesnt bother me long as i know where its coming from lol

Yeah i think thats what it is. Those valves/vacuum tubes above the dr side valve cover.

Far as this goes im not sure. When my buddy bought the engine we were told it was a 4bbl engine, but it had the 2bbl intake sitting on it, held in w/ 2 bolts. Guy told us it was only there to keep things covered. We never figured out how to check it for sure. The engine had plenty of power, could spin 35s all day long, and chirp them into 2nd and 3rd gear. But it did have an edelbrock intake 650 carb and lt headers on it too lol. How would I be able to tell for certain if I got the 2bbl or 4bbl engine?

 

MAC makes headers for the exhaust conversion. I like them.


Mine was carb so I can't help you with that computer gizmo stuff.

 

Yeah it goes to a port on the lower intake which is ducted internally to the heads which also have a special EGR port in the back of the central exhaust port for this purpose. The same heads are used on the 5.8 so it too could have use the same style EGR setup, but for some reason it doesn't. Anyway.. the 5.0 EGR tube is flexible so can be adapted to fit a 5.8 with headers...




The 4bbl motor got a bigger cam so if the motor is still assembled, simply remove a valve cover and 1 rocker, mount a dial indicator on the end of the pushrod and crank the motor over one revolution. If you measure about 0.277"(in) lift or 0.282"(ex) lift you have the 4bbl(351HO) motor, if you get about 0.260" lift you have the 2bbl version.

 

Just found out my 302 has a knock sensor... any ideas what I should do w/ it? Im well past the backing out point in this project, and need to know if theres a way to incorporate it into my 351w, or what I should do, where i should put it.... HELP!!!!

 

Did you finish this project yet? (I'd sure hope so) I'm looking at doing the swap when Ol Redd can retire from being my daily driver. Haven't decided a few things yet and a lot of those will resolve when the time comes to start the project. I will definitely come back around here to get some answers when I start the conversion

 

lol guess i should probably update this thread. Yes i finished the conversion, and ive put about 20k mi on the truck since. Couple things i ended up changing:
-the shorty headers i bought had the egr boss in the stock location for a 5.8, so i ended up just buying the 5.8 egr tube and using that.
- I did end up hooking up the PCV system, using a new valve, and moving the hose to the center of the intake tree.
-I also found that alot of the 302 sensors were not happy w/ a 351, so i had to buy the 5.8 versions. the O2 and the coolant temp for sure, i dont remember what other sensors i had to switch over. (the plugs are different between 5.0 & 5.8, it didnt like to run on a set of new 5.0s i had)
-i found it also didnt like to run on my 302s injectors. I tried to clean/rebuild them, but it didnt solve the problem. I had to buy 8 new injectors to finally get it running/idling good.
-it still doesnt idle great when cold, im attributing that to the difference in engine size using the stock programming. once warmed up and the o2 starts adjusting, it idles great

 

The 351HO cam is a bit more radical than what is typically installed in an EFI motor.. lobe separation is less and intake duration longer, so cold idle will be rougher than stock.. I see the same thing with the XE264 that I have in my 5.0.

How do you like the motor overall?

 

Does anybody know how this conversion goes when using an already EFI equipped 351W? I'd like to find a 92-96 3/4 ton parts truck and use the motor out of it. To me, a rebuild would be a nice project anyway so I don't mind going that route. What has to be done to use a fuel injected 351? Talking abut the HO and the cam has me wondering this...

 

Another option for myself is to use a 351 Modified because a good friend of mine has one that he isn't going to use and he offered it to me for cheap, would that bolt up to the 4r70W and would it use the same motor mounts? relocation is a pain in the *** and I would really like to avoid that...
Sorry to hijack this thread!

 

I dont think the 351M will bolt up to your trans, i believe it uses the 460 bolt pattern. No probs if you use an already efi equipped truck.

Conanski, overall im pretty happy with it. The truck drives down the road now and doesnt always feel like it is hauling a heavy load, it cruses quite comfortably. And when i want to get on it, the truck has the power to speed up and pass people now. couple things im not so fond of are the 4r70w doesnt seem to shift at the correct points at all, likes to shift into OD way too soon, and hold it too long before downshifting on its own. in town ill be doing 40ish and the truck will shift into OD, and drop the rpms down to about 1100. sounds like its bogged way down.

 

Sounds like I'll be investing in an E4OD or a C6 if I go with the 351M. TCI makes a nice C6 for around 1200 bucks, and it seems like that would be well worth it.
Another question, does the C6 bolt up to the later 351W? Reading a Jegs mag it shows a C6 for a 351 but it doesn't have engine years.

 

as long as its a windsor, it will bolt up. My engine block is originally an 84 model year, and it bolted up just fine to my 95 transmission.

 

It goes even easier, unplug the 5.0 and plug in the 5.8.. with a few little details to take care of. You want a '94+ 5.8 to get a roller motor.