Hi,

It's a 1999.

 

And it only has a three speed? I didn't think they did that trick in 99.

Yeah, a 5.9, and 46RE trans, along with the harness, and flashing your pcm to accommodate the bigger motor, would likely leave you with a big smile on your face. Gas mileage may stay about the same, or, you might see a bit better/worse. (depends on if your trans really doesn't have O/D or not....)

Is there a "Tow/Haul" button on the end of your shift lever?

 

Lol me either. No there is no such button. I know it's been abused because the guy who sold it to me used to tow a very large toy hauler with the poor thing.

 

Hey, I know!...... Pull a build sheet for your van. Go here, feed it your vin, and see what comes up. It should tell you what trans is in it.

 

LOL I know...when I first got my van with the 3.9 I thought it would be OK...I ended up going through the whole motor (for various reasons) and replaced the heads, timing chain and put in 1.7 roller rockers. I also advanced the timing chain 2 degrees. It really helped and probably added 20-30 HP but the torque only gained some. It still was much better than stock and is the reason why I kept the motor in there for 8 years.

I took a trip from Florida to Pennsylvania a year before I came up in my van here and it did horrible on the hills around here. 30-45MPH was top speed many times, so that is why I decided to keep the van and swap the motor out before I moved up here into the mountains

The 5.8 in my shortie is so much better concerning drivability. No issue up and down the hills and interstate drive, now that I have overdrive, is much more enjoyable. Gas mileage did improve and I think it is mostly from now having overdrive. Now, my van loaded is 6000+lbs - with me just in it its about 5500. I was getting 9-12 in town and 12-14 on the highway with the 3.9 Now I am getting 11-13 in town and 15-16 highway. The 5.8 did wake it up, but off the line it isn't a tire roaster, but it is still so much better than before. I would say 0-60 now is 9 seconds and I can get to 80+ with ease now.

Swapping, from the technical aspect, is pretty easy. We did have to shorten the driveshaft, add the tranny computer for the 46RE, and replace the whole wiring harness with the 360s but it came out great! The only thing is that if you don't change the steering column out, (this is guess) you will still be using the 3.9 wiring with makes the indicator circle (PRNDL) non-operational. We tested the tranny with the computer and every thing works - just not that indicator light. I haven't tried to fix it, but the only thing is you lose the OD cancel button on the stick. It is an annoyance - it still doesn't change the proper operation...

Let me know if you want more info