5.7 Swap into D150 Completed

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Yoox_II

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The engine swap from a carb'd 318 to a 5.7 hemi is finally (pretty much) done. Just getting O2 sensors put in the exhaust and kickdown linkage adjusted, some other small things like that then it's ready to go. I kept the 727 transmission. Will make a video in a couple days to show you guys. It's just in time for the colder weather which will be nice not to deal with stalling and unpredictable carbureted issues this winter. I will miss the durability of the 318 but that's about it.
 

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Treburkulosis

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Very nice! Do you have any pics of the swap as you were doing it?
 
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Yoox_II

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The majority of it was done by a mechanic who I know in my town. I was able to stop by a few times each week and help out where and when I could. I definitely learned a lot. I have a few pictures but nothing extremely detailed. I could however answer any questions on how it was done though
 

RonJon '06

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That's Awesome! How much of the truck's original wiring is integrated with the new PCM? Which adapter plate did you use to mate the 5.7 to the 727 and are you still using the original accelerator pedal?
 
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Yoox_II

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That's Awesome! How much of the truck's original wiring is integrated with the new PCM? Which adapter plate did you use to mate the 5.7 to the 727 and are you still using the original accelerator pedal?

I bought a wiring harness from hotwireauto.com specifically made for putting a 5.7 in an old Mopar vehicle. Obviously none of the lighting and horn wiring etc was affected by this, but pretty much everything else was replaced. It came in a fully labeled bundle of wires which made it (sort of) easy to just plug in. I used a flexplate/flywheel made by Mopar performance I believe, it's specifically made for coupling the 727 with the 5.7 engine. Using the original accelerator pedal yes.... but not the original throttle linkage. The cable still leads from the pedal up to the engine bay, but then I bought a bell crank assembly (found only on 03 rams) that basially converts the mechanical workings of the throttle pedal and cable to a computer controlled throttle. The bell crank assembly is essentially the bridge between a mechanic input, but a computerized output.

I was the mechanic's "parts hunter" and researcher, so I figured *most of this out on my own and online. Then he made it happen using his knowledge of installation etc.
 

Mega-Hemi

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That's a nice looking truck, and now it'll run like a beast too. I'd love to have a project truck like that.
 

fasthemiram12

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Got the same project in the works...
What motor mounts were used?
 

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Yoox_II

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What did you end up using for the gas tank and fuel pump?

Using the stock gas tank but retrofitted a 2012 ram fuel pump. I gas gauge isn't working as of yet. I found some semi brake lines that are rated for 138psi and a hemi needs 57psi, plus they were 10x cheaper than buying actual fuel lines
 

crazzywolfie

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you could have got rubber fuel line fairly cheap. i am pretty sure even the "low pressure" fuel line is rated for 60 psi or something like that. i know the guys at my local store have mixed it up a few times when i tell them i want fuel line. it is for a fuel injected vehicle but i don't need something rated for 70-80psi. you could have also got steel fuel line. the stuff is cheap but pretty hard to bend.
 

usaf2006

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I'm sure I'm not the only one who would love to see a video walk around and start up!
 
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Yoox_II

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Good points crazzywolfie, I was in a bit of a time crunch with finding parts so I jumped on the semi brake lines when I found them for so cheap. The some steal lines would have been nicer looking for sure. I will post a link to a walk around once I make one hopefully this weekend. Maybe try a 0-60 video as well.

Question, a G3 hemi is rated at like 398HP. Obviously it's a little lower since it's not brand new, maybe 375? Anyway, is there any reason I WONT be able to notice a power difference? Will my old 727 transmission restrict the hemi's power? Also, the engine seems to rev very low when in gear, so I might need to get a different rear end to wake it up a bit
 

crazzywolfie

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you should notice a big difference. the 727 won't restrict the power but it is not as efficient as newer transmissions. that brings up the next point. you may want to save for a transmission swap or rebuild because that newly gained power will likely cause the transmission to fail especially if you are driving it like a race truck. i wouldn't touch the gears in the rear. they are pretty much matched to work with the gears in the transmission. you don't want the engine to be reving high at highway speed. if it shift at a lower rpm with your foot to the floor then you probably need to keep adjusting the kick down linkage. it effects when and were it shifts or kicks down. i know i got the one on my 89 adjusted so that you barely notice 2nd gear is gone
 

usaf2006

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Well gen ii hemis are supposedly 345 hp, but most stock motors dyno around 260. I'm guessing you're in the mid 300s.
 

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