92 ram motor swap 3.9 to 318 or bigger
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92 ram motor swap 3.9 to 318 or bigger
I have a 92 ram D150 with a 3.9 and want to swap for a v8 but was told it would be very pricy and complecated . Seeking advice on if this can be done without breaking the bank
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Joined: Jan 2008
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From: Sioux Falls, SD
Welcome to DF!
Part of the expense is unless you have the manual tranny, you'll have to swap the transmission out too. The V6's transmission cannot handle the power/torque of the V8s.
And for future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html
Part of the expense is unless you have the manual tranny, you'll have to swap the transmission out too. The V6's transmission cannot handle the power/torque of the V8s.
And for future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html
Legend
Joined: Jun 2009
Posts: 8,025
Likes: 72
From: orangeville ontario
it can be done but you almost need to find a parts truck to get what you need. you will need the under the hood wiring harness from the v8 and if you plan on keeping it fuel injected you will you will have to try find a 92 or 93 with 318 or a 93 with a 360 for the harness and the computer for whichever v8 you plan on using. you would also need the drivers side motor mount extension plate that you should be able to find on any 88-93 d150 or ramcharger. don't know id the d250's or d350'd have them.
There's been a lot of guys wanting to swap out the 3.9 for a 5.2 motor on a 2WD truck. There has been a lot of speculation on the motor mounts. Well here is the real deal:
The engine brackets from the 3.9 (below) will not fit the 5.2 motor.
You will need the engine brackets for the 5.2 (shown below). Hopefully your donor will have them already on. If not, take note of how the bracket bolts to the "ears" on the side of the motor. It should be on the front side of the "ears". Also, you will need the adapter bracket for the driver's side frame bracket. (shown below) This puts the mount forward and lower.
On the driver's side, the new frame bracket it is held in by 4 bolts instead of 3. The new bracket is mounted as shown below. The old triangle brackets for the frame are no longer needed.
On the passenger frame bracket, the first pic shows how the 3.9 mounts and the second pic is of the new location for the 5.2 motor. Once again, the triangle bracket is not needed. The motor mount is now bolted directly to the crossmember in the furthest forward location. Should be a dimple above the bolt hole.
This pic shows both sides mounted in the new locations. This pushes the mount forward and a little lower. Should be pretty much level and even now.
The engine brackets from the 3.9 (below) will not fit the 5.2 motor.
You will need the engine brackets for the 5.2 (shown below). Hopefully your donor will have them already on. If not, take note of how the bracket bolts to the "ears" on the side of the motor. It should be on the front side of the "ears". Also, you will need the adapter bracket for the driver's side frame bracket. (shown below) This puts the mount forward and lower.
On the driver's side, the new frame bracket it is held in by 4 bolts instead of 3. The new bracket is mounted as shown below. The old triangle brackets for the frame are no longer needed.
On the passenger frame bracket, the first pic shows how the 3.9 mounts and the second pic is of the new location for the 5.2 motor. Once again, the triangle bracket is not needed. The motor mount is now bolted directly to the crossmember in the furthest forward location. Should be a dimple above the bolt hole.
This pic shows both sides mounted in the new locations. This pushes the mount forward and a little lower. Should be pretty much level and even now.
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Joined: Aug 2010
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From: San Antonio, Texas
Hey 92Ram, do you know for sure what tranny is on your truck? I can only tell you about automatics since that was what mine is and that is what I researched. My 91 D150 had an A999 which is a medium duty 3 speed automatic transmission and has been used on 3.9's and 318's. A500 trannys are 4 speed automatics on 3.9's and 318's. A727 is the heavy duty 3 speed automatic and the A518 is the heavy duty 4 speed automatics which were used on 318's and 360's. A904's, according to my FSM were not used on trucks in 91 and so probably not on your 92 either. A999's can be used but longetivity may be an issue if you plan to use the truck for heavy towing. If that's the case, you may want to get the beefier A727/A518 trans. In any case, I would definately use a trans cooler and a deep pan to keep it cool.
As for the wiring harness, I noticed that the only difference was for the TBI temp sensor. It will run without it but this sensor is to help with hot restarts by enrichening the air fuel mixture. The transmission cooler line that goes to the passenger side of the radiator is bent in the wrong spot for the 318. I was able to bend it to go under the oil pan instead of around the front like the factory. Later on, I picked one up at the JY for a couple bucks. The kickdown linkage is different also. You will have the 3 piece linkage and the V8 will have a 1 piece rod. No more than $5 at the JY. The last part you will need is the computer.
IF you have a donor vehicle, all these parts will be there.
As for the wiring harness, I noticed that the only difference was for the TBI temp sensor. It will run without it but this sensor is to help with hot restarts by enrichening the air fuel mixture. The transmission cooler line that goes to the passenger side of the radiator is bent in the wrong spot for the 318. I was able to bend it to go under the oil pan instead of around the front like the factory. Later on, I picked one up at the JY for a couple bucks. The kickdown linkage is different also. You will have the 3 piece linkage and the V8 will have a 1 piece rod. No more than $5 at the JY. The last part you will need is the computer.
IF you have a donor vehicle, all these parts will be there.
Last edited by SixGun; May 16, 2013 at 06:44 PM.
Professional
Joined: Apr 2011
Posts: 175
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From: Minnesota
I am currently doing a 360 manual trans swap, but unlike you I am starting with a 318, so I have no converting to to on the engine side. Sixgun, you actually answered one of my questions, I was wondering why there were trans lines running to the rad, figured it had to be something like that. But anyways, this is one of those things where financially, it usually makes more sense to buy a different truck with what you want. That being said, if your anything like me you have become quite attached to your truck and would rather put more money into it than buy a different truck. To keep the costs lower, your best bet would be to find a donor truck (like previously stated) or you could go salvage yard shopping (that's what I did). As far as trans, like the others have said, either the a518 or the a727. Which one you choose depends on what the truck will be used for. If it will be traveling many miles, the OD on the 518 will provide better mpg.