[dana44]

Welcome to the forum for starters.

This can be a pretty easy swap, depending on exactly what you are looking for. A complete swap with electronics isn't too difficult to do, only thing I would be concerned with is the oil pan, transmission, and fuel pump. I don't know for sure if the oil pan bolt pattern is the same for the Magnum and the LA, gasket is definitely not the same, but there may be clearance issue with the sump, but pans can be altered easy enough if you have access to a welder, people do it all the time. The 727 in the RR will bolt to the Magnum without a problem, you might have an issue with the speedo depending on the year of the Magnum transmission, they became electronic after 1993(?), but the 727 will work just fine, gear ratios will remain the same. The Magnum does not have a fuel pump in the timing cover, the pump is in the gas tank. That may be a difficult thing to alter in short order, but there are proper aftermarket in line pumps that can handle the (45-55psi) pressure, a little extra plumbing may be needed, you may or may not have enough lines running back and forth, just use the truck lines and canister. Now, the interesting part will be how much electronics you want. The computer/engine/injectors/sensors harness is not bad at all volume-wise, at this point a wiring diagram would be needed to identify what is needed and what is disposable and how to power it. I would not try to swap over to a carb, electronic ignition (even though you have that distributor in the RR), and low pressure fuel pump (electric). why waste all the advantages of having the good running electronics. Last thing to check is the hood clearance, which is probably close with the Magnum barrel intake, but still a slight concern. It won't be a five minute job or even a weekend job, but it would be worth the effort, and exhaust should not be too bad to deal with.

 

[TWX]

If I remember right the Magnums got the 360LA's bottom dimensions, and there are aftermaket oil pans for this application if it doesn't fit for some reason. Obviously the oil pickup tube could be an issue if the sump is relocated.

If the truck has an overdrive then there'll be some clearance issues as the bigger transmission doesn't quite fit, but people have made new brackets for the tailshaft mount, and some have cut away the welded-in floorpan-hugging crossmember as well. If you do use the new transmission you'll need to use cooling lines as big as those with the new transmission, the older ones on the '73 are too small.

You didn't state the year of the truck, if it's an old D-series (up through '93) then doing the dash wiring should be fairly easy, even with the computer, as the D-series trucks had analog gauges. If it's newer then that's a different story, and I'm not really able to help you on that end.

You'll need to figure out if the computer samples speed from the differential. If it does then that's another area that'll need attention, but it's fairly likely that the truck and your car use the same axle housing/tubes, so you'd have to have an axle shop put shafts and hubs in with 5 on 4.5" bolt pattern.

 

[73roadrunninram]

My truck is an 2001 crew cab long bed for those who asked, and gauges arent an issue, before my pop passed he ordered digital gauges with all the hardware, so getting the,gauges to work wouldnt be too hard of an issue. I appreciate yalls replies, the Roadrunner has the hemi hump hood, and ive done the,measurements and almkst everything will bolt up except the trasmission mount along with the need of a new driveshaft. Im hoping with me and a bunch of my friends will be able to knock it out in a,few days. Assuming we dont hit a snag in settimg up the fuel system which is,probably my biggest fear next to the,computer parts.

 

[dana44]

The 2001 does have the electronic speed sensor in the rear end, which is why I recommended sticking with the 727 in there, but overdrive is a good thing, but not sure how that will work even with your dashboard and speedo, input for speed is in the rear end itself, and I am pretty sure the rear end in the '01 is wider than the RR. There are aftermarket trans mounts, given there are so many being swapped and all, but you will have to alter the sheetmetal between the seats for that overdrive unit, there is about an inch in diameter of the transmission overdrive compared to the size of the driveshaft tunnel, not an easy thing to do on a weekend with a bunch of buddies, but not impossible to do, just a bit of extra work there, time consuming to do it right. Keep the 727 for now and you are in good shape, need to figure out that speedo item.

What is your rear end ratio? The truck is either 3.55 or 3.90, so there is another thing the overdrive may not agree with if the RR is 3.23 (close to the 3.55), but if it is a 2.73 rear, that will be real hard on the overdrive, the 727 overcomes that problem, and the computer won't care if there aren't any transmission inputs, guys that have dropped manuals behind auto computers haven't had any problems or check engine lights for doing it.

 

[73roadrunninram]

I believe the rear end is a 3:90

 

[dana44]

Pretty good for a Roadrunner, and although that would be a good candidate for the overdrive transmission it does not fix the problem of not having a speedometer. The electronic speedometer is set up with a sensor on the rear end housing and the ring gear has a sprocket on it, the sensor runs close enough to it to count revolutions, like the timing for the fuel injectors/spark, so it is going to be an issue to ponder on your part.