5.9 magnum engine swap

[Fixitmg]

I am working on a 5.9 magnum engine swap into my 77 dually with a 4 speed. And I have a few questions for the guys who have done the swap before. first question is I am guessing I need to use the original clutch flywheel. 2) pilot bearing, which one should I use, I am guessing again I need to use the original motor pilot bearing number? the motors are supposed to be the same but this crank is different from what I read, but is the pilot bearing holes the same? 3) when I pulled the donor motor out I found what looks like a crank sensor on the rear of the donor motor flywheel. what is this, I don't understand why there is a crank sensor when they use a distributor still. Hopefully it is for the trans input speed and has nothing to do with the motor.
please help

 

[65 sporty]

Are you leaving the magnum fuel injected? Yes that is a crank sensor at the back of the engine and it reads off the reluctor on the flywheel. The magnum distributor only has a cam sensor inside. You will need a flywheel for a magnum with a manual trans

 

[Fixitmg]

yes I am , leaving the magnum stock. I did find out it was a crank sensor, which is what I thought. I really want to keep the trans, so I can use the grannie gear when I need it. and living here in Alaska I use it all the time.
so plan A is to purchase a 2001 flywheel which takes a 12 inch clutch and drill it to accept the 11 inch clutch. Dead Dodge Garage on you tube has done it with a stock 318 flywheel and a lathe which I don't have either of them.
Plan B is to just convert it to a Automatic, which I have a good donor truck to pull all the parts, I just think it will be a long labor then keeping the 4 speed.

 

[65 sporty]

Why would you want an 11" clutch over the 12? The 12" will hold more than the 11. What trans is in the truck now? NP435?

 

[Fixitmg]

well I don't know for sure on the trans code is I haven't been under the truck in a few minutes. But the research I have done is the 12 inch and the 11 inch clutch do not match with the number of splines and the size of the shaft, I have not been able to find a 12 inch clutch that matches the spin and size of shaft.
if you know of 12 inch clutch that will fit the original factory 4 speed in my 78 truck that would be helpful.

 

[JDMopar]

If you can get an 11" clutch disc that fits your truck now, and lay it beside the 12" disc for the later flywheel....just check to see if the 11" disc will work with the 12" pressure plate. You can use your existing bellhousing by just cutting the notch in the top for the crank sensor on the 5.9. That is, if the 12" flywheel will fit your existing bellhousing. You may end up having to take it one step farther and just use the 4WD stuff from the later truck the 5.9 came out of.

 

[7mopar]

If you can get an 11" clutch disc that fits your truck now, and lay it beside the 12" disc for the later flywheel....just check to see if the 11" disc will work with the 12" pressure plate. You can use your existing bellhousing by just cutting the notch in the top for the crank sensor on the 5.9. That is, if the 12" flywheel will fit your existing bellhousing. You may end up having to take it one step farther and just use the 4WD stuff from the later truck the 5.9 came out of.

That may cause some drive line issues using the newer bell housing and transmission.
I have had bell housings modified to except different transmissions. But finding a machine shop willing to do it could present a problem.