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460 swap!

57K views 110 replies 29 participants last post by  reptillikus 
#1 ·
Yeah, looks like its happening. Been looking on/off for a 351 for my dad's truck since he needs a motor, and ended up finding a 460/C6 combo (w/ harness & ECM), so i bought that instead. Plan is to drop the 460/C6 in my truck, then put my 351 in his truck, and i guess sell my small block C6.

Mess of stuff in the bed of my truck


Stainless headers, w/stainless ARP bolts holdin em in place.


Ive never seen headers like this before, the d.side wraps down under the engine behind the pan. Its designed to bolt up the factory dual-inlet cat.




Extra crap i dont need (egr, alt, smog pump, all other emissions crap)



I got a set of towers out of a junkyard so i can run stock motor mounts.






Also got a saginaw off a 460 van, thought i had a pic of that but i guess not. Ill get one when i put it on the motor.


So heres the plan. the motor ran strong when the truck was cut up so im not going to do anything to it other than change a couple seals, and clean up the valve covers & pan. Swap my 3G on, add a Saginaw, and eliminate the emissions.
Heres the fun part. My truck is an 88, and the engine is an 89. Unfortunately, 88 has a bastard harness, the 89-91 harness is different. So i have a lot of wiring to do. The engine harness is in good shape, the main control harness (the harness that connects the motor to the ECM, and connects to the lights/ starter relay etc) was butchered when the motor/tranms was pulled. Now, i saved the control harness from my p/u cab since it wasnt compatable with my truck (cab is a 90), so it looks like ill be using that harness instead of my 88. But this means i must change all the connectors that go from the control harness to the chassis harness. This is the easiest way to make it all work i think. So tomorrow im going to the junkyard to either find a 88 460 to steal the engine harness off of (what are the odds of that?), or im chopping up a junkyard 89-91 harness to get the connectors i need to retrofit mine.
 
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#5 ·
We'll see what happens, but i hope to have it running by the end of the month. Not complete, but atleast running. I want it done before April 1st.



I have no idea who's headers they are. I was hoping someone on FSB knew, because the collector is a weird size. 2.75" ID pipe, but the bolt pattern is bigger so i cant find gaskets. Going to make my own.




Ok, i was at the junkyard all day today, scored some sweet stuff


Up top, new intake hoses because that gray plastic piece in mine is busted.
New oil cooler since i didnt get mine with the motor.
All the wires/connectors i need to update my chassis harness.
Different fuel rails for the 460.
The plastic panels for the sides of the 40/20 bench in my F250.

All for $30 :rockon

Tomorrow im going to start working on the wiring harness. I need to pin out the 88 & the 90 harnesses to figure out which wire goes where, and then i can splice the connectors in.

As for the fuel rails, i found this interesting. My 88 351, has both fuel lines connect to the rail at the back of the motor. My 89 460 has the fuel lines connect at the front of the motor, meaning i would have needed new fuel lines. Well, i found this rail in a ~96ish truck, and it has the fuel lines connect at the back of the motor just like my 351, so i should be able to just connect my stock lines to it and be done :thumbup
 
#14 ·
My notes from the 88 harness.


But now i have a big problem. the bulkhead fitting for the '90 harness has pins in different places. looking at the two, i see 5 pins that are not in the right spot. Comnparing the 89 & 90 harnesses, they are pinned almost identical. (the 89 harness came w/ the motor, but is butchered by previous owner, the 90 harness came with my cab)

This is a huge problem. I need it pinned like the 88, for it to work with the dash harness. I see myself as having three options.
#1, i rewire my 88 chassis harness to plug into the 90 control harness, and then re-pin the bulkhead connector to plug into the 88 dash harness. This seems to be the easier of the two, but now i have a custom harness so if anything happens to it ill be ****ed.

#2, completely rewire the motor harness to plug into the 88 main control harness. This is gonna be a huge project because it will require grafting the 351 harness onto the 460 since the ECM connector is on the 88s engine harness. This will make it kind of like a 88 F350 harness, but is not something i want to do because it will be crazy hard to do.

#3, find a engine harness from a 1988 F350 w/ 460. Somehow i dont see this as very feasible.


My father has the complete Ford wiring diagrams book for a 1990 which he is going to mail to me, so thats half the battle right there.
Here is what i need. I need to know the color code for all the wires that go to the tailgate on a 1988 bronco, so i can eliminate those wires from the bulkhead fitting. Those could very well be the wires that dont match up with the main control harness im using. At this point i dont know what too many of the wires are for, only where they go. I know the parts guys at the local Ford dealer, so im going to see if i can get these diagrams tomorrow.
 
#15 ·
Notes on the '90







Some interesting info.

Both harnesses have 24 wires. All of the similar pins in the bulkhead connectors go to the same places, and most are the same colors.
The 88 has 7 wires the 90 does NOT have. The pins arent even in the 90's bulkhead connector. I suspect 4 of these are for the tailgate. The other 3 i have no idea, as of yet. Possible they have to do with the dual vs. single fuel pump setup in 88 vs. 90? I dont know yet.

The 90 has ~8 wires that, while they have cooresponding pins on the 88's bulkhead connector, they dont go to the chassis in the 88 harness. Tomorrow i need to ohm out these pins on the 88 harness, to see where they go (maybe to the engine or elsewhere? or possible for the dual tank setup the 90 had?)


The wiring for the O2 sensor is different too. Rock Auto lists a different O2 sensor for each year, but the Ford p/ns seem to be the same? Not sure yet. The 88 has a 3-wire O2 sensor, the plug on the 90 harness has 4 wires. I think the difference is that the 90 has a ground wire in the plug, i dont think the 88 did.
 
#16 ·
It would appear most every wire swaps, except for the TFI, O2 & VSS, and im pretty sure ive figured out the wiring for the O2, and the VSS. Looks like they simplified it for 89-91.

My next hurdle is the TFI. Looking at the 88 harness, there are 3 Red/Lt Blue wires. Looks like one comes from the column and goes to the NSS, then one returns from there, and the 3rd goes to the TFI. The 89 & 90 harnesses are simplified and only need 2. One comes from the column and goes to the NSS & the other returns. Well, it returns, and then goes out another connector in a different place, to go to the motor. Heres where it gets weird. It looks like Ford changed all the pinouts on the engine harness from 89 to 90. So, since the 89 harness is butchered and im using the 90 one, i think i will have to re-pin all four conenctors on the motor to match the 90 stuff.
Current plan for tomorrow is to finish double checking all my other connections for the chassis harness (on paper for now), and then go compare pinouts at the motor for 89 vs. 90. It doesnt make sense for them to change it, but ive already confirmed the TFI signal is moved to a different connector, so most of the others must be wrong too. Fortunately ive removed all the emissions so that eliminates a few wires right there. Ill look into it tomorrow and see what i find.
 
#18 ·
I dont understand it. I mean, if it worked in 89, why change it all for 90? The color codes for the engine's sensors are the same for the 88 & 89 and match most of the diagrams ive seen, but the 90 harness despite being laid out the same as the 89, has a different color code, and the pinout is different. Its really weird. I have a feeling im going to have to check every single wire for the truck :banghead
 
#20 ·
Ok, ive got this wiring thing figured out.


Heres how it goes. Trying to repin both the engine harness & the main control harness, just so i can then splice it into my chassis harness, is a waste of time. Ive got a simpler, wayyyyyy better solution: grafting the 351w harness onto the 460. I know it sounds crazy, but it will totally work, and its actually not that hard to do. It is not a bolt-in swap, so to speak, as there is some wiring that must be done.

So here we go. First up, remove the engine harness. Of note is the 89 fuel rail, and how the fuel lines connect to it right behind where the a/c compressor would be


Here is my junkyard rail swapped in place, with the fuel lines connecting in the back like the 351 does



And here is where i began exploring the electrical. It seems both engines use pretty much the same sensors. The TPS is different; on the small blocks the sensor has a pigtail, on the 460 the wiring harness plugs right into it. So that connector must be changed.
Aside from that, the only other difference is the distributor.

88 351w


89 460


Im not really sure why the difference, but after looking at the wiring, i see it just intersects the PIP & the Signal Return, on their way to the TFI. The third is in parallel w/ the TFI. So unless somebody tells me not to, tomorrow im going to splice that plug into the 88's harness. It will be easy enough to do.





Ok, so the 88's harness has a 'secondary' harness. It goes to all 8 injectors, the ECT, TPS & IAC. The wires are also all way too long, which means i can shorten them all up, and have a nice neat engine harness :thumbup


Before i cut anything. You can see how much extra wire i have to work with:



This is where im at right now. That secondary harness is done, ill get a pic of it tomorrow. The 'main' harness runs from the EEC connector up the firewall and to the back of the motor where it plugs into the secondary harness. But it also goes to the TFI/Distributor, TAD, TAB, EVR, EGR, A/C, the oil pressure sender, that other stupid little sensor (i forget what it is), the MAP sensor, and a few grounds. At this point i have this entire harness de-loomed. I have completely removed the TAD, TAB, EVR, EGR & A/C circuits. I have added an EGR Eliminator up at the EEC connector to take care of the EGR. I am also re-routing several of the wires, because i think the 88 harness looks like crap with wires run haphazardly across the motor. Ive got about 8 hours into all this today, but all thats left now is to modify the TFI/Dist connections, organize a few wires and then re-loom everything. So if it doesnt snow, and i get to work on the truck tomorrow, then i should have no problem finishing the wiring harness :rockon
 
#21 ·
Wiring harness is done.



Once i lay it out on the motor for good, i will put all those push-in fasteners back on the loom so it stays in place.


Also as you may have noticed, the hood is off. Thats cuz the front-clip is off too :thumbup



Doubler removed


351/C6 coming out
 
#23 ·
I have a love/hate relationship with wiring. I get lost when im doing it. I put 7 hours into that on friday, and didnt even realize it :toothless I like everything to be nice, neat & organized, and the OEM stuff isnt. And since i wanted to properly delete the emissions & a/c, i figured the only way to do it right, was to strip it and re-do everything. So ive got ~10 hours of work into those 2 harnesses (and 3 rolls of electric tape), plus however many hours i spent reverse engineering Ford's diagrams.
But, now itll all just go in and work, and itll still be wired like an 88 bronco.

Now today i have to shovel snow, but maybe this week ill be able to get everything else ready so i can put the 460/C6 in.
 
#25 ·
I will try to keep it informative, i promise :thumbup



Ok, so before the motor can go in, i need to adress the motor mount issue. Well, Everyone says the conversion mounts are junk, and after seeing how beefy the OEM 460 mounts are i have to agree. So i went to the junkyard and got a pair of motor mount towers torched out of a truck. Only cost me $30 for the pair :thumbup
Before you ask, yes the towers are discontinued by Ford, i looked into it. There are a couple passenger side mounts left scattered in random dealers across the US, but thats it. They also cost more than what i got my pair for.

Towers, fresh from the junkyard


Excess frame removed, and wire-wheeled in preparation for paint


My frame, with the small block mounts still installed


Just like the big block towers, passenger side is 4 bolts, driver side is bolt (2) & rivet (4).

Passenger side towers, big block in front


Driver side towers, big block in front



....and installed in my frame.


I saved the bolts from all 4 towers because they were all in great shape, which left me with more than enough bolts to replace all the rivets i knocked out.

With this done, theres really not much left for me to do before the 460 goes in :thumbup
 
#32 ·
Good idea, but too late, i finished the harness on saturday. I know it sounds like it was a disaster but it wasnt that bad to do. I can deal with wiring, its not all that bad, if youve got the patience.



Wonder where i got the idea :toothless
 
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