My dad is about to rebuild is 1990 302EFI. It can hardly pull our cabin cruiser (previously yanked around like a toy by a '79 460). What, besides the ignition and firing order is different about the 351W EFI and the 302 EFI. Will the intake and exhaust manifolds fit? What about motormounts? I know the AOD will bolt up. What about the computer. Is there a jumper to change engines or do you have to completely change the computer? If the computer must be changed, does the wiring harness have to be changed? If anyone knows please say so.

 

You'll need a new lower intake, the 351 is wider than the 302. I think you will have to get a new computer, but I'm not positive. You should be able to use your wiring harness, but you may have to rearange the order of the injector plugs because of the new firing order. Also, there is a steel tube that is part of the smog system which runs from one head to the other on the back of the engine. It's all solid, so you'll either have to cut it and add a new piece in, or get a new one.

You're engine mounts will line right up. You should have no problem with your exhaust manifolds, but due to the 351's extra width, you may have to do a little exhaust work for your pipes to line up.

I put a carberauted 351 in place of a EFI-302 in my '90 f-150, and plan to switch back to EFI once I get the parts. I've been having a hard time finding a junk yard intake. Anyway, hope this helps.

 

Thanks for the advice. I did a little more research. I looked at wiring diagrams. The 351W deletes some of the equipment such as the knock sensor, and power steering sensor. The injector wiring is the same.
I diagramed the injector and ignition timing. Here is how it works: The four "corner" injectors (1,4,5,8) are on one circuit. Call this circuit A. The "interior" injectors (2,3,6,7) are on another. Call this circuit B. Circuit A is live first and then B. While B is live, the cylinders fed by circuit A are firing. While circuit A is live the cylinders fed by circuit B are firing. It would look like this on the 302: 1-5-4-2-6-3-7-8, A-A-A-B-B-B-B-A. It would look like this on the 351W: 1-3-7-2-6-5-4-8, A-B-B-B-B-A-A-A. The wiring is the same just the timing would be off.
There is one sure way to solve this and that is to get a new computer. I live in AZ and all our junk yards are stripped of their fuel injection cars before they get off the wrecking truck. The other option I'm looking into is programming. I looked on the web and found binary codes for the EEC-IV system. To my understanding this computer module is used in everything from an escort to a diesel super-duty (under 1996). If I could program it I think I would be set (key word is think).
Last questions, do 302 EFI heads fit on a 351W? If they don't, does it matter if the donor 351W heads are from an EFI or a carb. model? Are the oil pans the same? Is the mounting hardware the same for the alternator, powersteering pump, A/C compressor, and anything else that would hang on the front?

 

I have a question for you about the smog pipe on the back of the heads. Is that as 351 only thing?

I thought I grabbeda 302 from the wrecking yard, but If I didn't then that changes everything!



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302 and 351 head are interchangable. you need to make sure they are drilled for emmision lines on the back. That is the metal tube I mentioned. You'll need a new oil pan. The one I put on mine was a dual sump, with the larger sump in the rear. I would have prefered a regular rear sump, but it fit. Your ac/powersteering bracket will bolt right up. It bolts to the head and timing cover and has two holes for the bolt on the timing cover: one for 302, one for 351. The alternator, smog pump bracket also bolts up, but I don't think the lower hole on the smog pump lined up, I had to make a little plate to space it out. no big deal.

About programing the computer, I've never heard of anyone doing it, but it'd be cool if you could. I remeber an article in Popular Electronics asking about this and the editors seemed to think it was impossible. Don't really know.

hotrodford: The smog pump pipe was on my 302. I put in a carberauted 351 and eliminated the pipe. I'm pretty sure the 351's would have it as well since the systems were so similar.

 

Ok, I know mine has that stupid pipe. And last year when I pulled my engine to replace all the gaskets (didn't need to replace them all but "better to be safe thatn sorry"), I had to take some brake cleaner to that pipe and the valve that was connected to it, and just let it sit & soak. It was so clogged up with carbon it was unreal! Both the tube, and the ports/tube in both heads were plugged up as well. No wonder the truck wouldn't run right. Plus my entire egr port was clogged, But I never checked the pipe. (doh, I just remembered that. Could that be the reason this thing runs so crappy?) It does read an EGR code everytime I pull the codes from the computer. And I have replaced everything EGR related. I am looking at a new intake for my truck. I found an oval port truck intake, similar to what the mustangs ran, but It was on a truck. Both the upper and lower are correct. (well, they aren't together, but I can fix that. The guy has about 3 or 4 lowers like that, but only 1 upper. I am not sure if it was for a 351 or not though.) But I am going to find out! I think that would give me some more power, because of the more conventional shaped runners.

Plus at the same time I could clean out the egr pipe if it's plugged up.


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This is kind of late, but for what its worth:
I just finished putting an 88 351W EFI in my 87 was 302 F150. I got the engine and tranny complete with the frame from the E350 it came from. The engine physically dropped in with no extra work (other than changing to truck motor mounts). I used the wiring harness from the truck and everything had a place to connect to except the knock sensor. I used the ignition setup from the 302. As well, I switched to the 302 emissions setup. The injector tubes into the exhaust manifolds were all cut and pinched off (well, mostly pinched off. A couple leak) For exhaust I used the 351 manifolds and the van lead down pipes that came with it. To fit the pipes I had to remove the one angle bracket at the tranny crossmember. The cat hit the junk pile since it was full of holes and most of the substrate fell out (I will need to find some cats for the truck before my birthday next year or else they won't E-test it and I'll be SOL) I had some custom pipes made to run from the lead down pipes to the glasspacks and then out a pair of stock tailpipes. It looks tame but it sounds really cool, especially for a rustbucket winter beater. I used the accesory drive from the 302 but I need to custom make some brackets to support the PS/AC parts. The 88 and later PS/AC bracket fits both the 302 and the 351 but mine had the wrong PS pump (van style) on it and you need to pull the pulleys to remove them. It starts and runs on the 302 computer and I have been driving it around on it so far. It is ok, but cannot run WOT or it hits dead spots and sometimes misses at higher RPM. It also idles 2-300 rpm higher than the 302 but does none of the hunting the 302 did. I hope to get a new computer very soon and see what kind of a difference this makes. This might be too late, but I hope it helps.

 

While the bolt PATTERN is the same, 302 specific heads have 7/16" bolt holes that have to be drilled out to 1/2" for 351 use. 351 specific heads should use a shim/washer kit to mount on a 302. Also since, I THINK, the late 70's the intake manifold water ports are the same, the early 351 heads used an L shaped water port and an extra manifold bolt.

 

I don't know about the extra bolt but you are right about the L-shaped coolant passage. I remember seeing something about that in one of my gasket kit's instructions. The Edelbrock intake (Performer 351W) I got for my other truck has an L-shaped port as well; it's just a little plate intruding into the passage that I'm going to grind out when I put my new cam and timing chain in.