1978 j10 (amc 360 3/4 ton axles) ls engine swap

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rikki
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Joined: Wed Oct 07, 2020 6:33 pm

1978 j10 (amc 360 3/4 ton axles) ls engine swap

Post by rikki »

Hello new to this site, I have a ex navy 1978 jeep j10 mostly stock except 4in lift and 35in tires and upgraded shocks. have also done a little
engine work rv cam, offy dual plane intake and 4bbl carb. still working on the interior hard to find stock seat.
anyway been thinking of swapping the amc 360 to an ls engine. what is all involved, can I use the th400 trans?
thanks
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Stuka
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Re: 1978 j10 (amc 360 3/4 ton axles) ls engine swap

Post by Stuka »

The Th400 is an AMC bolt pattern.

To go LS you would need an adapter. But then you run into the issue that the QuadraTrac may not live behind the power an LS makes. Most swap the engine, trans, and t-case. That way you get over drive and such.

What is your goal for the truck? Is there anything wrong with the 360?

The title mentions 3/4 ton axles. Are these in it now, or would that be included in the swap?
2017 JKU Rubicon
Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

Topic author
rikki
Posts: 2
Joined: Wed Oct 07, 2020 6:33 pm

Re: 1978 j10 (amc 360 3/4 ton axles) ls engine swap

Post by rikki »

the 360 and trans just rebuilt then parked, have a rv comcam offy quadrajet intake. just want to get rid of the vacuum line, haven't had it running for a while so will have to go thru every thing again. the 3/4 ton axles are on the truck, I think it was ordered that way for the navy.
just want something more reliable and better fuel with ls engine maybe trans, and t-case.
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j10jim
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Re: 1978 j10 (amc 360 3/4 ton axles) ls engine swap

Post by j10jim »

Put a Howell EFI unit on the 360. Best thing I have done to make it reliable and trail usable. Gets rid of most of the smog stuff and vacuum lines.
Going to take a long time to make up the costs in fuel savings. If the engine was toast, then an LS swap would make sense.
1980 J10/20
Rusty's 4" lift, 2" body lift, old Cliffhanger front bumper, 35" tires, 65 dash w Speedhut gauges.
Xtrusion Overland rack system, Tepui tent, 1/2 decked system.

LONG time member of ifsja.org, FSJ-List and some others...
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1978J10REDWHITE
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Re: 1978 j10 (amc 360 3/4 ton axles) ls engine swap

Post by 1978J10REDWHITE »

I also am looking at the Howell EFI for my 78 J10360.
It runs Very good at 88K Orig miles.

So, the Howell TBI are tried and true systems from GM, Cost is a bit sure, looking for the reliability and efficiency of it.
How was the process & has been in general since instal?
I would think once done are great all around & flawless as most all EFI usually are.
thx
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