[jammons5126]

so i was wondering about an engine swap. i am thinking either the 5.2 or 5.9. i have a 2002 dodge dakota. which would be better for my truck. i have a 3.9 in it right now and i am upgrading the rear axle and front end. let me know what i can do if i can put a bigger engine in it then i will be happy. if i have to do any madding to get it in there let me know thanks.

 

[RJ_Hythloday]

I'm going from a 5.2 to a 5.9, it's way more than I first expected. Others have done a 3.9 to 5.9 though so that'd be a better place to look. As long as you're doing all that other work and doing a swap no reason not to do a 5.9.

 

[ncroadracer73]

There's almost nothing externally different about the 5.2 and 5.9 so swapping to either one is esentially the same. Actually they're almost the same externally as the 3.9 ..... you just have 2 extra cyliniders. As long as you have the same tranny/torque converter that came with the 5.2/5.9 you'll be good. The 2 are balanced differently but if you keep them mated to their original tranny you're ok.

Really all you need for the swap is the V8's engine/tranny combo, engine wiring harness, and PCM. You should be able to reuse your exhaust and driveshaft if I'm not mistaken. You'll have to remove your radiator shroud because the V8 is longer, and the V8's use a different intake tube but if you're using an aftermarket CAI or round filter you'll be fine.

All your external accessories (water pump, a/c,alternator,pwr.steering) is the same between the 3.9-5.2-5.9.

You'll need the V8 motor mounts .... they're different from the 3.9 so make sure you get those with the motor.

I just did a swap putting a 99 5.9 R/T drivetrain into a 2000 Dakota that came with the 3.9. Was pretty easy really.

 

[jammons5126]

There's almost nothing externally different about the 5.2 and 5.9 so swapping to either one is esentially the same. Actually they're almost the same externally as the 3.9 ..... you just have 2 extra cyliniders. As long as you have the same tranny/torque converter that came with the 5.2/5.9 you'll be good. The 2 are balanced differently but if you keep them mated to their original tranny you're ok.

Really all you need for the swap is the V8's engine/tranny combo, engine wiring harness, and PCM. You should be able to reuse your exhaust and driveshaft if I'm not mistaken. You'll have to remove your radiator shroud because the V8 is longer, and the V8's use a different intake tube but if you're using an aftermarket CAI or round filter you'll be fine.

All your external accessories (water pump, a/c,alternator,pwr.steering) is the same between the 3.9-5.2-5.9.

You'll need the V8 motor mounts .... they're different from the 3.9 so make sure you get those with the motor.

I just did a swap putting a 99 5.9 R/T drivetrain into a 2000 Dakota that came with the 3.9. Was pretty easy really.

my plan is to buy a dakota with a 5.9 in it take it out rebuild it clean it up and replace any parts needed replacing. what about the ignition. would that be hard to change.

 

[ncroadracer73]

what about the ignition. would that be hard to change.

Nobody's ever convinced me that some high dollar aftermarket ignition does anything for performance. It's just pretty and you can say "I've got "such and such ignition" on my truck. There's nothing wrong with your stock system. Replace the distributor cap, rotor and plug wires with quality aftermarket replacements (napa is good) or factory mopar pieces. Also, don't waste your money on plutonium/platinum/rhodium etc. spark plugs ..... just use good ole standard Champion plugs the truck came with.

These, of course, are my opinions and I'm sure others will disagree but nobody's ever proved to me that aftermarket ignition parts do anything for your truck except dress up the engine bay.

 

[jammons5126]

Nobody's ever convinced me that some high dollar aftermarket ignition does anything for performance. It's just pretty and you can say "I've got "such and such ignition" on my truck. There's nothing wrong with your stock system. Replace the distributor cap, rotor and plug wires with quality aftermarket replacements (napa is good) or factory mopar pieces. Also, don't waste your money on plutonium/platinum/rhodium etc. spark plugs ..... just use good ole standard Champion plugs the truck came with.

These, of course, are my opinions and I'm sure others will disagree but nobody's ever proved to me that aftermarket ignition parts do anything for your truck except dress up the engine bay.

sorry i should of expalined more. i am talking about starting it up. when i do a swap to a 5.9 i wont be able to use my key that i have right now will i.

 

[ncroadracer73]

Sure, your keyswitch won't be affected. Your truck won't even know you have changed the engine.

 

[jammons5126]

Sure, your keyswitch won't be affected. Your truck won't even know you have changed the engine.

alright sounds good. thanks.

 

[trevor]

I'm pretty sure your motor mounts are the same. The reason why I'm pretty sure is that I don't know if they were different in 02. I know on my 99 I reused my 3.9 motor mounts on my 5.2 swap. Mine was a 4x4, so they were not just motor mounts, they were motor, front diff and tranny mounts. Your truck being a 4x4 makes it that much more of a pain in the ass.

Y-pipe fits on a v8 the same as a v6

You dont need a complete wiring harness. If you're good with wiring you can add in the 2 extra injectors.

 

[ncroadracer73]

You might be right on the motor mount thing ...... for some reason I thought they were different. I'm not all that familiar with the 4WD's ..... didn't even dawn on me that his is 4WD ..... I've only owned 2WD Dakotas.

If he's got a donor truck, might as well use the donor harness. Plus, depending on the year of the V8, he may have different numbers of O2 sensors. My 2000 V6 had 2 ..... the 99 5.9 has 4! I had to use the 99 harness and run a wire from the ECU to the downstream 02 sensor.

 

[trevor]

You might be right on the motor mount thing ...... for some reason I thought they were different. I'm not all that familiar with the 4WD's ..... didn't even dawn on me that his is 4WD ..... I've only owned 2WD Dakotas.

If he's got a donor truck, might as well use the donor harness. Plus, depending on the year of the V8, he may have different numbers of O2 sensors. My 2000 V6 had 2 ..... the 99 5.9 has 4! I had to use the 99 harness and run a wire from the ECU to the downstream 02 sensor.

You're right about the o2 sensors. My truck after the swap was always looking for some upstream sensors that didnt exist, so I got a check engine for that. I never got a chance to fix it before it was written off.

 

[jammons5126]

You might be right on the motor mount thing ...... for some reason I thought they were different. I'm not all that familiar with the 4WD's ..... didn't even dawn on me that his is 4WD ..... I've only owned 2WD Dakotas.

If he's got a donor truck, might as well use the donor harness. Plus, depending on the year of the V8, he may have different numbers of O2 sensors. My 2000 V6 had 2 ..... the 99 5.9 has 4! I had to use the 99 harness and run a wire from the ECU to the downstream 02 sensor.

i do have a donor truck. its sitting in a junk yard right now. engine starts up just the rear end is torn to hell. that dont matter i am wanting the engine out of it. its a 2001.

 

[ncroadracer73]

You're right about the o2 sensors. My truck after the swap was always looking for some upstream sensors that didnt exist, so I got a check engine for that. I never got a chance to fix it before it was written off.

Yeah, here in North Carolina you can't get a tag without passing emissions testing and without all the O2 sensors working properly kinda hard to do that.

 

[jammons5126]

Yeah, here in North Carolina you can't get a tag without passing emissions testing and without all the O2 sensors working properly kinda hard to do that.

they dont do emissions test here. i mean they do but they only check if we are running NOS.

 

[ncroadracer73]

God, I wish we were like that ..... it's a real PITA sometimes:rant:

 

[jammons5126]

God, I wish we were like that ..... it's a real PITA sometimes:rant:

for our inspections they only worry about lights, and if we have a complete exhaust system.

 

[trevor]

There are no inspections here at all. There is a safety done when a vehicle changes hands, but it's a complete joke.