New to the forum here. Been doing some poking around on magnum conversions / swaps. Haven't found much info. What I'm looking for is options and opinions on which path to take. I'll start asking about parts once I decide on which way to go. So here we go....

The situation:
I have a '84 crew cab dually w/360 4bbl and NP435 2wd. The motor is old, tired and gets low single digit mpg. Want to upgrade to 5.9 magnum status. I have a 5.9 magnum and accompaning auto from a '98 3/4 ton truck. The engine is complete from TB to pan (needs rebuilt), minus flexplate, computers and wiring. The trans is missing the TC and I'm guessing the VSS (theres a gaping 2" hole on the left side). I also have a engine harness for a '99 truck that came with the motor and trans. The truck is used to tow my race car and other heavy loads, no daily driving. Optimally I would like to find a donor '93 1 ton 5.9/auto. But finding one has been like trying to find a unicorn.

What I want to do:
#1 Rebuild the motor to stock with a cam change for more low end. Retain stock intake and injectors. Use a stand-alone computer system like universal Holley Commander, MSD box, headers, etc. Have the NP435 rebuilt to like new for roughly a grand.

#2 Option 1 and add on a non-electronic 4-speed auto later down the road.

#3 Do a completely stock rebuild. Use the '99 harness I have and hook it up to a stock or MP ECU. Back it up with the auto, rebuilt to HD/3500 status. Have my driveshafts shortened and install a trans x-member from donor auto truck of same vintage. Install something like a B&M mega truck floor shifter. New electric autometer gauges.

For fuel delivery, I was thinking of a Holley/Walbro external inline pump and a universal AFPR.

3 trans questions:
1. What is the nomenclature for this trans? (A-727, A-413 etc.)
2. Is it electronically controlled?
3. If it is electronic, will I require a body computer along with the ECU and trans computer?

Either option is expensive, but option 1 looks the least $$. So tell me what you think and any other quirks that might be associated with an option.

Thanks

 

in 98 I believe that the tranny used was a 46re, and yeah if that's the case it is electronically controlled. I don't know if there is a seperate TCU or if it is controlled by the ECU.

I'd go with option 4 - rebuild the magnum with a 4" stroker crank for a hair over 400 cid, mild cam for torque, wire it up for fuel injection, and mate it to your manual tranny. The 46re is famous for not handling abuse very well, but I gather with proper cooling they can be ok.

 

Thanks for the tranny info! Stroker motor is out of the question for me. The conversion alone is expensive enough. The conversion to EFI for gas saving is my game plan. Thanks for idea though.

 

The 46RE is controlled by the engine computer.

You'd be better off with a 94-95 engine/harness/computer and a 46RH.

You're also missing an option. Diesel swap. If I were going through all the trouble of swapping something into a truck...especially a crew cab dually (heavy beast), it would definitely be a CTD. Your mileage even with the magnum isn't going to get out of the single digits very far with the 360 [&:]

 

ROM,
As sweet as a CTD would be, I don't want to imagine the cost for that. Thing is that the motor, tranny and harness that I have, I got for free. Anyways, ya I been reading that the 46RE's are a bit of a PITA, whereas the RH's are, for the most part, trouble free. So you think I should trade up my RE for a RH and get a 94-95 computer for an automatic? What about my '99 harness? Will that work with the 94-95 ECU or are the connectors different?

 

The '99 harness won't work with the 94-95 transmission or computer. The RH would be a better transmission. The electronically controlled transmissions have been known to be weaker.