3.9L to V8 Swap?

MCIntoDarkness · Jun 13, 2017

So just curious, how much money would I be looking at to do a swap in my '98 Ram from the 3.9L V6 to a V8. I'd also be looking at refreshing the V8 before putting it in the truck, but nothing to crazy. New intake, plenum fix, new timing stuff, heads, etc. Canned tune to open it up a bit. Basically bulletproofing it.

Currently the truck has the 3.9L V6 in it with a automatic transmission. No cruise control or fancy stuff like that.

Keep in mind, I'd likely be paying somebody to swap this for me, since I have neither the time, or the technical knowhow to do it myself. Yeah, I could bolt it in, but hooking everything up is a no-go.

I figure trying to build up this truck the way I want it would be cheaper than buying a new vehicle, especially for a senior about to head to college.

dapepper9 · Jun 13, 2017

It really depends on who does the work. Heads will be spendy, plenum cheap. Need a full harness, pcm and trans to go with

Johnnymac2k6 · Jun 13, 2017

The easiest way to acomplish this would be an entire pullout driveline from a donor truck with a 5.9. between the v6 and v8. The trans, harness, ecm, etc etc etc is all unique. You aren't going to drop a 5.9 in front of a v6 trans, with a v6 ecm, and hook up a few wires and go.
Now if you find a wrecked donor for $600 with low miles...sure...fairly feasable. But...tons of labor...

In the end, since you aren't capable of doing most of the labor yourself , your assumption of "this will be cheaper than buying another 5.9 truck in the long run" is very niave. Way too much labor. I'm sure you can find a cheap 2nd Gen with a 360 cheaper than hiring someone to swap you engines.

MCIntoDarkness · Jun 13, 2017

Johnnymac2k6 said:
The easiest way to acomplish this would be an entire pullout driveline from a donor truck with a 5.9. between the v6 and v8. The trans, harness, ecm, etc etc etc is all unique. You aren't going to drop a 5.9 in front of a v6 trans, with a v6 ecm, and hook up a few wires and go.
Now if you find a wrecked donor for $600 with low miles...sure...fairly feasable. But...tons of labor...

In the end, since you aren't capable of doing most of the labor yourself , your assumption of "this will be cheaper than buying another 5.9 truck in the long run" is very niave. Way too much labor. I'm sure you can find a cheap 2nd Gen with a 360 cheaper than hiring someone to swap you engines.

Well, I would buy a new truck, but I really have an attachment to this one. It was my grandfathers, but when he passed it came to me. Now I like the V6, but it just doesn't do what I want it to do. It literally will top out at 40mph pulling a empty trailer up a small to medium sized hill here in Mississippi. That's with overdrive off.

I figure I could build up the new engine myself. I know several people around here that have wrecked trucks that may contain reasonably low mile engines suitable for refreshing.

My issue comes with actually swapping the engines. I'm almost certain I'd mess up something with the ECU or the harness. Not that I'm particularly worried about it, I was planning on ditching the stock gauge cluster anyways for a custom one with aftermarket gauges, but I know there's sensors and a whole lot more besides gauges that rely on the ECU.

So based on this, what would you guys recommend? For reference, I have about $6000 I can spend on this. Swap engines, or try to freshen up the V6 the best I can. Selling the truck or getting a new one is pretty much a no go, I'm way too attached to it.

Shadow_Death · Jun 13, 2017

Johnnymac2k6 said:
The easiest way to acomplish this would be an entire pullout driveline from a donor truck with a 5.9. between the v6 and v8. The trans, harness, ecm, etc etc etc is all unique. You aren't going to drop a 5.9 in front of a v6 trans, with a v6 ecm, and hook up a few wires and go.
Now if you find a wrecked donor for $600 with low miles...sure...fairly feasable. But...tons of labor...

In the end, since you aren't capable of doing most of the labor yourself , your assumption of "this will be cheaper than buying another 5.9 truck in the long run" is very niave. Way too much labor. I'm sure you can find a cheap 2nd Gen with a 360 cheaper than hiring someone to swap you engines.

Yup this is exactly what I was thinking. The only option worth while IMO when you go engine swap would be just to find an old 4BT to swap in. I mean if you're going to do all that work might as well make it unique.

Johnnymac2k6 · Jun 14, 2017

If you have 6K stored up, keep that truck as a cruiser/2nd vehicle, and buy another 2nd gen.

Again if you MUST do a v8 swap, i'm sure you need a v8 trans, ecm, complete wiring harness...and 100 other things.

OR.... but a wrecked v8 COMPLETE truck for under 2K, and tell a shop you have 4K to pay them to swap EVERYTHING over.

again, I understand the sentimental value, but that would be fairly ridiculous IMO, when you can keep it as a spare vehicle, and probably even get a 3rd gen with the 6K you have.

https://youngstown.craigslist.org/cto/6175566677.html

https://youngstown.craigslist.org/cto/6175566677.html

https://youngstown.craigslist.org/cto/6168581409.html

https://youngstown.craigslist.org/cto/6173791252.html

https://youngstown.craigslist.org/pts/6161456985.html

take your pick

MCIntoDarkness · Jun 14, 2017

I think what I'm gonna do, I'm gonna keep my truck and try to build it up as best as I can. I've been looking at the Dodge Dakota's with the 3.9L and I've seen some nice little performance tips. I've got a ton of other things I want to do with this truck, and my motor is in good shape, it just needs to be refreshed.

Shadow_Death · Jun 14, 2017

If it's a v8 swap you want and you're looking into some Dakotas you can probably find a Dakota with a 318. They're pretty common where I live, actually more common than the v6 counter parts. You'd have your V8 and a Dakota in 1 package.

MCIntoDarkness · Jun 15, 2017

Shadow_Death said:
If it's a v8 swap you want and you're looking into some Dakotas you can probably find a Dakota with a 318. They're pretty common where I live, actually more common than the v6 counter parts. You'd have your V8 and a Dakota in 1 package.

Well it's not that I want a Dakota, I was just looking at some of the performance tricks those guys use on their 3.9L's. Many say you can pick up an extra 5-10hp by just switching to a electric fan and aluminum radiator. A lot of them recommend the colder temperature spark plugs from NGK or Champion and the 180 degree thermostat. A lot of others combine those with a cold-air intake or a more open air filter and a different exhaust. The Flowmaster 40 series seems to be the trend among the guys on the Dakota forums.

I most definitely don't want a Dakota, lol, too small of a truck for me. :roflsquared:

MCIntoDarkness · Jun 15, 2017

Another question I have is, who makes a good timing set for the 3.9? I don't know if mine is shot or not, but since I'm refreshing the engine, might as well replace it while I'm there.

So right now I'm looking at all this, from top down.

New cold-air intake
Machined and modified throttle body from Hughes
New aluminum plenum plate and Fel-Pro gasket
New heads/head gasket
New timing chain/gears
Convert to electric fan (help on a good fan and how to hook it up would be appreciated)

For some miscellaneous items

New spark plugs
New wires
Cap/rotor
New oil pressure sender
New coil (need recommendations on this)
Gasket replacement throughout
Change trans fluid/filter
Change differential fluid
Replace radiator
Various cleanup and dress-up (thinking about getting some green loom or some braided hoses to brighten up an otherwise dull engine bay)

Anything else you guys would recommend?

Yeret · Jun 16, 2017

Have you talked to Ryan at all? I'm not sure if he tunes the sixers or not but if he does, he'll be the one to turn to if you really want to wake the engine up.

Come to think of it, did the Magnum sixers receive the same "death flash" as the eighters?

And I'd look around a little bit before shelling out for the Hughes throttle body. I hear that their claims are total BS. I got mine on eBay for a hundred bucks but I don't think that the guy offers them anymore. You might check out The Fastman. I think Dodge Dude here uses one of their products.

For the ignition coil, if you want to replace it, just get a genuine OEM one. I've heard bad things about running high-output aftermarket coils on our trucks. Pepper knows more about this than I do. As far as ignition stuff goes, you don't need anything fancy, just some good quality OEM-spec stuff. Even Ryan considers aftermarket stuff for our trucks a waste of money.

For a grand, I know Engine Quest makes uprated as well as improved cylinder heads for the V8's. I'm not sure if they make them for the V6.

If you're not going to tow or haul anything, you might consider 75-90 gear oil (not 80-90!). I personally use 75-140 Royal Purple but that was back when I actually did haul heavy stuff. If I ever change it again, I might go to 75-90 since it's supposed to generate less resistance and free up a few ponies.

dapepper9 · Jun 16, 2017

Big Gulp is pure BS. Hipotek is the way to go. Oem coil from the DEALER is your best option as mentioned. Aftermarket replacements or "upgrades" like accell and MSD have been known to fry the PCM

MCIntoDarkness · Jun 16, 2017

Yeret said:
Have you talked to Ryan at all? I'm not sure if he tunes the sixers or not but if he does, he'll be the one to turn to if you really want to wake the engine up.

Come to think of it, did the Magnum sixers receive the same "death flash" as the eighters?

And I'd look around a little bit before shelling out for the Hughes throttle body. I hear that their claims are total BS. I got mine on eBay for a hundred bucks but I don't think that the guy offers them anymore. You might check out The Fastman. I think Dodge Dude here uses one of their products.

For the ignition coil, if you want to replace it, just get a genuine OEM one. I've heard bad things about running high-output aftermarket coils on our trucks. Pepper knows more about this than I do. As far as ignition stuff goes, you don't need anything fancy, just some good quality OEM-spec stuff. Even Ryan considers aftermarket stuff for our trucks a waste of money.

For a grand, I know Engine Quest makes uprated as well as improved cylinder heads for the V8's. I'm not sure if they make them for the V6.

If you're not going to tow or haul anything, you might consider 75-90 gear oil (not 80-90!). I personally use 75-140 Royal Purple but that was back when I actually did haul heavy stuff. If I ever change it again, I might go to 75-90 since it's supposed to generate less resistance and free up a few ponies.

I haven't talked to Ryan yet. I do plan on it once I get all my planned upgrades mapped out. Hopefully within a few months.

As far as the gear oil goes, I do town stuff, but it's usually not much. Trailer and lawn-mower, or trailer and ATV.

MCIntoDarkness · Jun 16, 2017

dapepper9 said:
Big Gulp is pure BS. Hipotek is the way to go. Oem coil from the DEALER is your best option as mentioned. Aftermarket replacements or "upgrades" like accell and MSD have been known to fry the PCM

I'm assuming Big Gulp is the throttle body. I'll go to the dealer for the coil, and I'll just get the NAPA Gold distributor cap/rotor.

3.9L to V8 Swap?

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