The definitive list...

Magnum Engine Swaps

  1. j par

    j par Well-hung Member

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    Is there a definitive list that someone has made in a thread? Likely should be a sticky for this part of the Forum...
    Like you have to have this flexplate or flywheel, you have to have this harmonic balancer.. this is the adapter you buy for the front of the cam to run a mechanical fuel pump? You have to have x oil pan with x oil pump tube...??? Even the obvious if you want to run a carburetor you have to have a Magnum compatible intake manifold..?
    Thank you for anybody's help on this...
     
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    • Syleng1

      Syleng1 Karma is real and Life is short... FABO Gold Member

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      I think you definitely need to put down a Mopar engine in a Mopar car. That should be #1 on the list.
      2nd I want to see Paint on an engine. Rusty blocks are not good.
      3rd I want to see gasoline. You MUST run gasoline for an engine to run. Maybe 3b) would be propane- but that’s hard to buy all the time.
      Okay JPar- off my soap box
      :lol:
       
    • R4Sedan

      R4Sedan Larry FABO Gold Member

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      • j par

        j par Well-hung Member

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      • Bobzilla

        Bobzilla Well-Known Member

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        I have not seen a one stop shopping list and every time people ask questions about Magnums, a lot of misinformation pollutes the threads.

        Nobody I know of currently sells an SFI approved flex plate for 5.9 Magnum balance. You can get the neutral balance B&M flex plate and cut it out to match the correct ones they no longer make, but you lose the SFI. B&M 10241 is the small diameter 904 trans with Magnum 5.9 balance. B&M 10242 is the larger diameter 727 trans with 5.9 Magnum balance. You can use the factory 5.9 Magnum weighted flex plate from later models and you just need to elongate one torque converter hole to line up, but this is more for stock and lower horsepower street builds. The 5.2 Magnum flex plate is neutral, so the current B&M neutral balance works fine. Any 5.9 Magnum running an aftermarket rotating assembly that is neutral balanced obviously accepts the B&M neutral balanced flex plates. There is a Mopar weight kit that can be welded to the torque converter for 5.9 Magnum balance and then you use a neutral balance flex plate. I forget the part number for that one.

        Only the factory style Magnum flex plates work with the factory crankshaft sensor location for factory Magnum EFI.

        All Magnum engines use the same oil pan. No difference for 5.2 and 5.9. A Magnum can run any LA 360 oil pan and pickup combo just like an LA engine, and can use LA oil pan gaskets, even when a Magnum timing cover is retained. Magnum one piece oil pan gasket can be used with an LA 360 oil pan, but the front steps in the pan will need to be filled with large gobs of silicone or right stuff sealer. I don't know if a current oil pan that is Magnum specific to allow the one piece Magnum oil pan gasket to be used without all the extra silicone. You can cut the top of an LA oil pan off along with the front seal area and weld on the same cutout from a Magnum truck pan and then you have a perfect flange for the Magnum one piece oil pan gasket.

        A Magnum timing cover have no opening for a mechanical fuel pump and will not physically clear the mechanical fuel pump eccentric. If the Magnum timing cover is retained yo must use an electric fuel pump.

        Hughes engines sells the adapter for the short snout Magnum cam to use a fuel pump eccentric.

        LA heads can be used on Magnum engines IF proper rocker arms are used with pushrod oiling, such as Comp Ultra Pro Magnum and all brands that are copies of those, such as PRW and Speedmaster. Oiling modifications can also be made to the head to add an external oil line, but I have not personally done that one.

        Intake manifolds; yikes. Mopar made several different version M1 intakes. Some single planes had LA bolt pattern with Magnum thermostat and bypass hose. Some single planes were Magnum bolt pattern with Magnum thermostat and bypass hose. Both versions were available with or without fuel injection bosses cast in and both had the four barrel carb flange. Mopar also made two barrel fuel injection single plane manifolds that accepted the stock throttle body. Mopar also made some Magnum bolt pattern dual plane carb flange manifolds.
        Edelbrock currently makes the only aftermarket intake with Magnum thermostat and bypass hose. The carb version is sold everywhere as an Edelbrock brand. Hughes engines sells the fuel injection version under their own brand name. The chines copy manifolds with dual bolt pattern all currently use LA thermostat and bypass hose. This complicates things when running Magnum timing cover and retaining Magnum serpentine drive and air conditioning.

        Magnum engine blocks with some LA headers require slight grinding on the left side rear Magnum engine mount boss to clear the header pipe. Magnum blocks can be run with older LA style starters if the block is celaranced around the starter. Easier and better to run the smaller Nippondenso starter used on all Magnum trucks.

        If retaining Magnum factory fuel injection, there are couple of tuning options for the OBD2 PCM that came on the trucks, identified by three smaller connectors. SCT has been doing programming for these for use. HP Tuners just announce support these last year. I think Syked ECU tuning supports them as well. Older OBD1 PCMs with one large connector are not programmable.

        I am sure there is more, but this what I remember off the top of my head.
         
        Last edited: Sep 4, 2020
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        • JDMopar

          JDMopar Well-Known Member

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          I'll add to the wish list! If someone has swapped in a Magnum and kept factory OBD2 EFI, it would be nice if they would post the year of their motor and wiring, and which wires you need to make the motor run. If I can't find something like that before I put the 98 5.9 Magnum in my old truck....I'll try to figure it out and put it in this section.
           
        • Bobzilla

          Bobzilla Well-Known Member

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          I was going to put together a list and show the connectors in pictures but have not had time.
          The year of the engine does not matter, for the most. Neither does what vehicle it came out of, although van harnesses have the PCM mounted high up front making their harness weird to use in a car.
          You can even put an OBD2 harness, injectors, and PCM onto an older OBD1 engine And it will run as an OBD2.
          Some early OBD1 engines had EGR valves, so that would need to be blocked for this.

          The stuff that stays hooked up is sensors like CKP, Cam sync (distributor), TPS, MAP, ECT, O2, and IAT. An output that stay would be IAC.
          Stuff you don’t need for it to run is things like evap canister purge and air conditioning compressor. If running air conditioning, keep the compressor clutch and connect high and low side AC pressure switches.

          From memory again, so I know I missed some.
           
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          • rbkt65

            rbkt65 FABO Gold Member FABO Gold Member

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            thanks and keep the info coming. more people out there than you think need this info. thanks again.
             
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            • j par

              j par Well-hung Member

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              Here's the scenario...
              My son has a 1976 Power Wagon in Colorado. I took out the 318 in the granny four-speed and put in an LA 360 and an automatic pretty much stock besides a factory cast iron 4 barrel intake and a 1406 Edelbrock... It's got power steering..
              If I was to pick up a 360 Magnum out of a truck at a Pick-n-Pull for under $200 with a 6-month warranty here in Portland Oregon and drove it out to him to do the swap and have everything prepared what would I need?...
              That is the real question. I have to bring almost everything to make it happen...
              the last thing I want to do is get there and find out I've got to order some part that takes a week or two to get or something crazy and expensive...
              Beyond gaskets I would need the intake manifold? I would need to grab the engine with valve covers and it's on flexplate? I would put all the LA timing cover and so forth on it... I would need to order the little cam from Hughes engines to put on the snout for the fuel pump... why do I remember someone talking about a special harmonic balancer? Or something to hold the belt drive on the harmonic balancer? Do I need the factory Magnum one or can I put the LA one on? I'm assuming the LA exhaust manifolds will bolt right on..? I'm assuming I will pull the distributor out of the LA and drop it right into the Magnum?.. motor mounts will bolt right up? Starter transmission bolts everything no problem? And he has the old fashioned starter witch it's kind of fun... from what I gather the oil pan doesn't need to be attached if I bring it from one truck to the next? Thank you for everybody's help....
              ??????????.....
               
            • 70aarcuda

              70aarcuda Master Hoader of SBM FABO Gold Member

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              They can list the parts needed to built that 500 hp 318 in there too....would save alot of bandwidth on the internet....
               
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              • j par

                j par Well-hung Member

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                No they can't... Save that comment for the fantasy thread... A Magnum swap can be done...
                 
              • JDMopar

                JDMopar Well-Known Member

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                You can use the flex plate that will be on the 5.9 Magnum, but will have to oblong 1 hole for the 727 converter to bolt to it. The motor mounts on his existing 360 should bolt right to the 5.9 (shims and all if you reused the prior 318 mounts), and since the 5.9 will come out of a truck or van, supposedly the existing 5.9 rear sump pan will work in his truck. I'm sure you know you need one of those dual bolt pattern Chinese intakes unless you have lucked into an Edelbrock or MP intake. I have no idea what kind of rigging you will need to do for the throttle cable and kick down linkage? It's a challenge doing long distance wrenching. Every time my idiot sister in law's POS Honda Elephant breaks down, I'm expected to drive 70 miles to fix it. Last time it happened, I took my trailer and drug it home. I had it fixed in a few hours.....and played dumb for 2 weeks like I was still trying to fix it in hopes she'd get tired of no wheels and get one of her many boyfriends to fix it. :rolleyes: Good luck to you.
                :thumbsup:
                 
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                • JDMopar

                  JDMopar Well-Known Member

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                  @Bobzilla Thanks. I have the entire underhood wiring from the 98 3500 truck that my motor came from, fuse/relay box and all. I may have lucked into a 98 wiring schematic to help narrow down the keeps and discards on the wiring. Like you though, finding the time is most of the problem....lol.
                   
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                  • 66fyssh

                    66fyssh Don't Stop Believin' FABO Gold Member

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                    Gabe did a "Recommended Parts Recap" towards the end of his DIY Magnum Swap in his How-to. Lots of other real-life swap info in there also.

                    Diy - Magnum Swap!!
                     
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                    • replicaracer43

                      replicaracer43 Grumpy Old Man

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                      The ballancer situation is because the earlier magnums used a bolt on crank pulley, old LA pulleys will bolt up no problem. The later magnums had a serpentine belt made onto the ballancer, so you need the earlier ballancer. The offset weight on the 5.9 magnum is different than the LA 360 also, but I think you can buy a aftermarket ballancer with interchangeable weights.
                       
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                      • replicaracer43

                        replicaracer43 Grumpy Old Man

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                        I have done the same swap on a 79 d100, with all the factory electronics, it's not especially hard, but a lot of studying the schematic to determine what you can get rid of. One important thing is you need the PDC (underhood fuse box) as it has the relays you need for the fuel pump and ASD relay. If I can help, let me know!
                         
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                        • replicaracer43

                          replicaracer43 Grumpy Old Man

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                          Magnum oil pan will fit. LA motor mounts will fit. LA distributor fits. Get a intake, LA front cover, ALL his LA front accessories bolt right up. buy the huges cam extension to run fuel pump. Magnum flexplate should allready be weighted, slot one hole and it will bolt right up to the old 727. LA exhaust manifolds will bolt up, but the ports are definitely different, I allways use the magnum manifolds when I do one, but that requires a redo of the Y pipe
                           
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                          • j par

                            j par Well-hung Member

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                            Oddly enough when I got this motor and transmission it was supposed to be out of a rebuilt 1975 Power Wagon. I split them apart and put the motor on my engine stand to reseal Andre clean it up as it had great compression and revealed a double roller timing chain and very clean Springs and rocker arms as if indeed it had been rebuilt recently. It has performed well since. But with that said the torque converter had no weights on it? I didn't see any on the flywheel as well? So knowing that this can't be right I welded weights on the torque converter either side of the drain plug from another 360 torque converter that I had.. the truck ran smooth. The previous owner bought the whole entire truck as a rust bucket and kept the frame and motor and sold the motor and tranny and transfer case to me. He said it felt like it had a bit of a cam in it which was probably the unbalance of the motor LOL..
                             
                          • JDMopar

                            JDMopar Well-Known Member

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                            :thumbsup: I'll definitely do that! Motor is going into 88 D100 beat around truck to haul wood, etc. I've been meaning to get up with you anyway, to see where you are in NC or ? You told me at Farmington, but I forgot. :realcrazy:
                             
                          • replicaracer43

                            replicaracer43 Grumpy Old Man

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                            Concord area...
                             
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                            • fishmens67

                              fishmens67 Well-Known Member

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                              j par is trying to take all the fun out of learning .
                              Hot rodders are pioneers of their own build.
                              and learning from mistakes is part of learning.
                               
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                              • JDMopar

                                JDMopar Well-Known Member

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                                @j par If you're getting a 5.9 Magnum from pick n pull, grab the mini starter while you're at it. Seems like I remember someone saying the old timey big starters will sometimes hit the rear boss that the Magnum mid mounts mounted to. Of course you could grind that boss off if he insists on the old starter, but the mini starters are SO much better and bolt right up. You may have to take the wiring adapter off of it, but that would be it.
                                 
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                                • 66fyssh

                                  66fyssh Don't Stop Believin' FABO Gold Member

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                                  There was a boss on my Magnum right where the mini starter mounted. I had to grind it off to get the starter to fit flush.

                                  Also had to grind some of the truck mount boss for clearance for the power steering gear. But a truck may have more room.
                                   
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                                  • 1968DodgeDart270

                                    1968DodgeDart270 Member

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                                    This list would be helpful for my current swap. Anyone know where I can source a bolt-on 7 rib serpentine crank pulley? I don't want underdrive. I've looked all over and can't find one.
                                     
                                  • RammerJammer75

                                    RammerJammer75 Well-Known Member

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                                    Something else to note when using a Magnum oil pan with an LA timing cover: you'll have to cut part of the one piece pan gasket that goes under the timing cover, use the LA oil pan to timing cover gasket and seal the seams between the two.
                                     
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