Hey guys and gals,

I am looking into the option of swapping out the 400 in my 77 highboy with something else. I have searched through the forums here and googled and was hoping to hear from any members that maybe have done a swap that they havent posted about or whatnot.

Im not looking for diesel swap info at this time, more looking into what guys have swapped in place of the 335 series engines, and if they had liked it or not. (sbf, bbf, fe, ls swaps, anything else?)

The 400 in my truck is working fine, but Im not a huge fan of it. Yes I have read how great they can be, and yes I know how some people think swapping engines out is comparable to selling your soul to the devil, please keep those comments to yourself.

The idea of a small block such as 351 does sound nice to me as my highboy is just used for puttering around the gravel roads and does very little work, but I would like to hear the comparisons, if you regretted it, etc. (for any swap you have done)

 

If you only putt around on gravel roads, what makes the current engine insufficient?

or maybe better asked....what is the reason for the swap?

fuel mileage
power
to be different
none of the above

 

Like you, my 400 works "fine" but I want to be able to drive this truck to the trail/on long road trips comfortably, reliably, and efficiently (read: gas). I just put this remanufactured motor in earlier this year but did so knowing I want to swap to a modern drivetrain in the near future. While a Coyote motor is ideal they are pricey (but not completely off my short list) so an LS motor is more likely in my future. I've helped put one in a Nova II recently and just loved how affordable it was, the reusable gaskets/o-rings, and just plain simple. To further complicate things I also have to pass smog in California otherwise I would have done it already.

By the time I spent the money to put an overdrive in my truck I'd be well on my way to a full engine/transmission swap of the LS variety. I've been thinking this over since I got the truck in 2017 and always land in the same spot.

 

A 385 series engine is the most common, easiest and most logical upgrade engine you could find.

 

I don't care for the feel of it, it's not great on power and it isn't great on fuel.

I'm not willing to sink any money into the engine, and I would rather try something else.

Plus I need a project. Apparently the 5 other ones I have, aren't enough to keep me busy haha

 

In the bump group, one guy installed the new Coyote platform into his highboy and he likes it? Just a thought as it still keeps it all ford and looks so much better.

 

If I were to do another swap I would wait and see what support comes along for the 7.3 the size and power make it look good on paper as long as the aftermarket comes along with a front accessory system and stand alone engine and trans systems if they haven't already

 

If there is anything that can be said to dissuade you from putting in an LS and pick any other Ford engine for your swap?

 

I have a coyote with 6r80 in my 68 highboy. I enjoy it. I lost a little low end torque compared to the 390FE it had but gained everywhere else. If I towed a lot I would have went diesel or 460. It is fun to run up to 7k though. Great daily and runs down the interstate 70 without problem. I pulled my car trailer (empty) for a couple hour trip and it did great.

Definitely not as cheap as a LS but using a f150 5.0 and changing cams makes it cheaper. Going with electric power steering assist is a way to avoid a ps pump. I made a simple bracket with a reverse gm type 2 pump to add power steering.

The 7.3 could be a good option too. I enjoy high rpm so I will stick with the coyote.

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Thats awesome! I would love a coyote, but in my area, they still are premium priced. I bet that thing drives like a dream with that coyote in there though. Would totally suit my needs, minus the initial cost.

 

Nope, Im not that brand loyal. Im mainly a ford guy (regarding trucks) but the ls is an amazing swap option these days.

 

I did two 460 swaps into 79 Broncos. EFI engines converted to carb. One is C6 other NP435. I like the 460's - came with factory serpentine belt system (used 460 E350 Saginaw pumps) which are also quieter and supposedly better.
As for power these two otherwise stock engines are very comparable to another 400 Bronco (recently sold) with 4bbl carb/intake and cam advance. Way more potential with the 460's I'm sure.

 

An LT engine (2014+ Chevy) is nearly a bolt in conversion- I am running one using original 74 Ford motor mounts and motor perches. These engines are leaps and bounds better than LS engines and are fairly inexpensive. I have a 74 f250 with this engine and also a 74 F350 with a 428 SCJ engine. The SCJ runs really great and is one strong big block. It can't even begin to keep up with the 5.3 LT, not to mention half the mileage and half the gears. A funny thing about modern engine swaps is that Chevy transmissions are easier to adapt to Ford NP205 t cases than most Ford transmissions. This being said, I will be ditching the LT powered truck for a cummins powered truck.

Attachment 281225

 

I converted a 75 f250 from a 360 with a c6, to a HP 300/4.9. with a zf5. Because of the head work, 4v carb, msd ignition, headers, I kept all the horse power and went from 10 mpg on the highway to 20 mpg. What I learned is that you have to work with the strengths of any engine. The strength of the 300 is hp down low, so keep the cam small or you lose the grunt. The recipe for amazing power is larger valves, 1.94 int and 1.6 exh, msd ignition, bowl work on the head, Hedman header with 1.5" tubes, an Offenhauser or Clifford intake, and a 500 cfm edelbrock or a 600 cfm Summit Racing 4v carb, both vacuum secondary carb. Use a hyper piston with a D shaped dish with 25 cc dish, and stay around 9.0 compression ratio. That combo will blow your mind. Rear gears not taller than 3.31, better at 3.50. Use 2.25" exhaust tube, dual to rear end, then 2 into 1 2.25". Most people want to put a small carb on these engines. But remember, the 300 is 75% of a 400 v8, with 4" cylinders and 3.98" stroke. That's a big gulp of air, so don't choke it down with a small carb. I've seen untold guys throw a Holley 390 cfm 4v on them, and wonder why they power is limited. And then I've seen guys toss a Holley 600 on them because they are inexpensive and everywhere, and they run fantastic. I've run many carbs on this engine while searching for that balance between mpg and thrilling power. I've tried the Autolite 485 and 600cfm, 750 and 800 cfm Quardajets, an edelbrock 500 cfm, a Holley 1848 (465 cfm), and the Summit Racing 600 cfm. For crazy power the Summit 600 blew everything away. The Edelbrock 500 had the best balance of power and mpg, but man, I sure loved that Summit 600.

The photo below shows the engine with an Autolite 4100, 485 cfm.

Attachment 281223

Here it is with an 800 cfm QJ on it.



And, I think I have a photo with the summit on it?

 

How have the 460s been regarding fuel vs the 400?