how hard would it be to swap from from a 3.9 to a 5.9
would it fit in? or would i have to mod it or something?
what else would i have to change if i went through with it?

i just want more power. ha

 

2nd gen gurus correct me if im wrong, but if its anything like a 1st gen, everything will bolt up, motor mounts and all, but you will have to change the fuel pump, the fuel rail, add 2 injectors, add the wiring for the 2 injectors, find a computer for the 5.9, and upgrade the tranny to a 46-re as opposed to the 42-re thats currently in there

 

Fuel pump will be fine. Fuel rail should come with the motor. and get a comp the same year if possible and motor too. 42re will hold just how long is the question I have had a 5.9 infront of mine for 2 years now. and I abuse it i do have a shift kit though, also running 5.38 gears and 38's now too.

 

to add to varsis note, get the wire harness for your year, for that engine, eliminates a lot of headaches splicing in the 2 extra injectors and the possible chances of electrical gremlins throwing check engine lights. cant guarantee you wont have any CELs once everything is hooked up and it runs. thats when you have to trace and troubleshoot your work and correct it.

 

thanks for the help guys

 

sorry to thread jack but varsis it's time for a new sig

 

Ok with the 5.9 being more commonly found in the full size ram trucks and vans, does the wire harness from the ram truck fit with no mods? What about model years? Is there a difference in model years that the wire harness will not fit? I just picked up a 1999 Dakota sport with no motor and am looking for an easy fast engine upgrade. It had the 3.9 but if I'm going to replace the motor I may as well go big or go home.

 

I don't blame you. I didn't realize they even put the 3.9 in a QC. Mine was slow enough in a CC.

 

I like Pbadgley's question, Im sure the motor is the same but can you use the ECU and the wiring harness?

Still bouncing between a 4bt and a 5.9