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4.0L into 2.8L '84 Bronco II.


'84 Bronco II

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My current 2.8L is dying fast and I need to either rebuild it or swap in a 4.0L. I am happy enough with the 2.8L around town, but it leaves me wanting on the highway and when I am running in the sand. Currently I have 35's a 4"lift and a 4 speed Toyo Kogyo with 3.73's. I want to put a 5 speed Toyo Kogyo and switch to 5.13's. I would like the power and fuel injection of the 4.0L, but all the complications, especially the wiring, scare me. Also I believe my '84 tank won't work with the fuel injection stuff. Is that true?
On the other hand, I do not want to spend money having my 2.8L rebuilt just to be disappointed with the power.
Bottom line: I don't want my truck down forever (It is my daily driver), I would like to comfortably cruise 70-75 mph down the highway, and I do not want to spend a fortune (I am thinking $3000 tops).

Hopefully someone can give me a little direction. Thanks in advance.
 
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kimcrwbr1

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1983
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ford
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5.0 carbed will give you the power your talking about just alot more mods. You will need to change the fuel tank for FI and the harness for the 4.0. Either way your looking at alot of work. Is your 2.8 still running on the computer and do you need to pass emissions. The duraspark swap could bring that engine to life for cheap that would be my first choice. I thought mine was croaking but it had good compression. Valve guide seals, manifold gasket, carb, dizzy and module and she starts/runs like new. Plus it holds oil a big plus!
 

kimcrwbr1

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5.0 carbed will give you the power your talking about just alot more mods. You will need to change the fuel tank for FI and the harness for the 4.0. Either way your looking at alot of work. Is your 2.8 still running on the computer and do you need to pass emissions. The duraspark swap could bring that engine to life for cheap that would be my first choice. I thought mine was croaking but it had good compression. Valve guide seals, manifold gasket, carb, dizzy and module and she starts/runs like new. Plus it holds oil a big plus!
Sorry I just noticed it has already been sparked you could do a long block 2.8 plug and play for reasonable and not be down long.
 

chilsam

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91 branger
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300 six
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Donor

Find a donor with a 4.0 grab the COMPLETE wiring harness dash & fuel lines I recently did this for my sons 89 loridr bought the donor for 300.00 sold parts i didn't need to buy parts i did and junked the body the whole swap cost me 50.00 + or -. and maybe 2 weeks of my time but i didn't work on it everyday either.My son luvs the power and mpg of the 4.0 over the 2.9.I recommend this swap HIGHLY! :icon_welder:
 

88_Eddie

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do the 4.0 swap. it would be about the same amount of work as rebuilding, but i think you'd come out cheaper and have more power. i'm gonna do one as soon as i have space to do it.
 

'84 Bronco II

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Thank you all for the replies.

My 2.8L has a bad cylinder I believe because the crank case is pressurizing and blowing oil out through the breather cap and dipstick tube. I had the head gaskets replaced and the heads rebuilt about a year and a half ago. I seemed to have more power then than it does now, and I was leaking almost no oil then.

As for the 4.0L swap, I would be extremely interested in keeping my stock dash. I think it looks better than the plastic second generation dashes. My truck has manual windows, manual locks, as well as a manual transmission. I am not sure why I would need to swap dashes out for a 4.0L seeing as all the gauges are analog and I believe the 4.0L oil pressure sensor plays nice with my current oil pressure gauge.

Also, my understanding is that the optimal 4.0L donor would be a '91 or '92 ranger with a manual transmission and no power windows or locks. Is this true? I have heard mention of PATS being a pain in the ass. Is this something I need to watch out for with this vintage of Ranger?

Also, a 5.0L is out of the question. It would get even worse fuel mileage, and I would have to swap out my current drive train. I don't even want or need V8 power.

Thanks again for all the replies.
 

'84 Bronco II

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I found a 4.0L from a '91 ranger with 102,000 miles on it for $575 with the harness. I am thinking about picking it up. What else do I need to swap it into my '84 besides a fuel injected gas tank? Will my current exhaust bolt up? Any thing else I should pull from the donor? Thanks.
 

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