1990 460 into 1991 F150, wiring differences?
 

There comes a time when a man realizes he has too many projects. Today is not that day.

Here's the short end of the story, ladies and gents. I sold off about 5 projects that i realized were just not going to fit my needs. I was officially out of the Bricknose body style, i had a couple of bullnoses and the rest were all "aero noses". It did hurt when i ended up selling off my 91 F150, aptly named, "the brick", but i purposely priced it high, hoping no one would bite, and someone bit.

Life knows when you need a pick me up, apparently. I got a call from a local acquaintance, who needed some 302 cores, wanted to trade. I had 302 cores , so i loaded up and drove down to see him.

Glad i brought Stay Puft and the trailer, because this followed me home.

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91 F150, 4x4, regular cab shortbox, with a gray interior, fairly fresh paint, and cost me little to nothing.

I'm a sucker for shortboxes, blue trucks, and grey interiors.

Just one issue with this particular blue shortbox...

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The 302 was already plucked.

That's fine, an old farmer wanted his "old junk truck" out from behind the barn anyway. So once again, I hook up the Stay Puft Marshmallow Truck, gas up, and drag home this lovely specimen.

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1990 F250, extended cab longbox, 4x4, 460, 5 speed.

I'm a sucker for big blocks with manuals.

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Got it in the shop...

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Started plucking goodies out.

So yes, I'm going to shove a 460/5 speed into a regular cab shortbox half ton. Its not that i couldnt build up a decent Windsor, or just toss in a straight six, i happened to trip across all these parts, and decided it sounded like the right type of fun.

Now that I have gotten the engine/trans/tcase out, and also set aside the driveshafts and all engine related bracketry, here is what else i was planning on keeping.

ECM
Dash and entire dash harness
Underhood harness
floor plate to switch to a manual trans floor
clutch pedal assembly
Frame mounts for big block motor mounts
Trans crossmember to properly match the ZF

Now the questions begin.
1) first off, is there anything else specifically i need to pull off of this truck to do this swap?
2) is the underhood harness, dash harness, and chassis harness in my 91 shortbox compatible, or do i need to swap over everything from the donor truck?
3) will the shortbox fuel system ( single rear tank only) feed the stock 460, or do i need to look at a different pump from a 3/4 or 1 ton with the big block option?
4) i realize that exhaust will need to be fabricated, that driveshaft will need to be built, that the truck will never qualify for smog compliance, and all the other little things that come with doing a swap like this. But is there some major hurdle that i may be overlooking?

I put a 460 from a 1990 F250 into my 1991 F150 in place of the original 300 Six. You will need to get the motor mount pedestals from the 460 as they are different than the 302s. You will find that the frame crossmember on the 460 truck is chamfered where the oil cooler attaches and your 302 frame is not. You will either need to accommodate this or eliminate the oil cooler (which is what I did). If you eliminate it, then you will need to open up the hole in the frame to allow for mounting the oil filter directly to the block or go with a remote mount oil filter. I did not notice this until I was lowering the engine into my truck so I put in a remote mount oil filter. The filter is mounted up behind the front bumper.

WRT to the wiring, just keep the underhood harnesses for the 460 and plug them into your existing bulkhead connecter on the firewall. The 302 wiring under the hood won't work as the 460 uses a remote mounted ignition module, for one thing. The dash harnesses and frame harnesses that are on your shortbed truck can be used. You will need the trans harness from the donor truck since you are converting to 5-speed (I did that on mine as well). Your existing fuel supply system is fine.

Jas88, thanks for the info, i knew someone, somewhere out there has been down this route before! if you have a link to a thread where you did the swap, drop it here, i'd love to see.

As far as the frame pedestals, i knew they were different, and already have them on my list. I also knew that the oil filter landed in a different spot, and, like you, I already have decided to ditch the oil cooler assembly. I'm going to use an oil filter adapter like this one:

https://www.summitracing.com/parts/f...view/make/ford

Its extremely similar to what ford put on the 460s in the early 80s bullnose trucks, to get the filter out and accessible. I'm also swapping my small block trucks to this setup, just so i dont need to fight the filter out of the hole.

I'm glad i dont need to take the time to snake out the entire chassis harness. Thats a relief.