So ive searched the forums but havent been able to find an answer for a few things. I have a 2002 Ram 5-speed 4x4 with a very dead 4.7L. Im considering swapping it to a 5.9L Magnum, and yes i know the Hemi makes more power but it is out of my budget. My questions are:

1) Will I need a 5.9 PCM out of a manual or would it be easier/possible to have an Auto one flashed? There are 2 Auto's in junkyards nearby, no manuals
2) Will the year of the PCM matter? Ive read that since i have a 2002, if i dont get a 2001-2003 PCM the gauges will not work because of the difference in the Bus.
3) Will the year of the engine matter? Ive heard that there was a change in cam gear or crank position sensor or something, but havent heard anything definitive.
4) Will I have to flash the PCM with my Vin & Milage?

Thanks ahead of time for any help, I want to get this figured out before i get too deep in a swap.

 

The 5.9 won't bolt to your trans.

 

To the Nv3500? Considering the 5.9 Magnum came from the factory with that trans in certain applications I'd be surprised. I've seen a couple sources say it bolts up fine, but hey that's why I'm here.

 

The NV3500 never came behind the 5.9 to the best of my knowledge. (was behind the 5.2's though. but, I am not always right either.......) The 4.7 has a different bellhousing bolt pattern than the old magnum v-8's.....

Edit: Apparently, the 5.9 and 4.7 bellhousing bolt patterns are close enough, only one bolt won't line up........ (at the top of the bellhousing, I think.) News to me.

 

I've found multiple sources (on this forum and elsewhere) that say the 4.7 has the same bolt pattern, and considering as you said it was behind the 5.2, which is also a magnum, it should. Never heard that one bolt won't line up, not that it would surprise me. Won't stop me though, I've had engines held in with alot less!

 

I don't think one missing bolt is going to break the bank.

I don't think any of the 1500's came with a manual trans, and 5.9..... however, if you could find one with the 5.2 and manual trans....... grab the PCM and wiring harness from that, and it should hook right up. (assuming you can find an 02 with 5.2 and manual..... "hens teeth" comes to mind.....) I really don't know if they even used the 5.2 in the third gen trucks.....

If you can't find one, then just get the pcm/harness from a 5.9 auto, and flash it for the 5.9. You are likely going to have to do that no matter which way you go.

Wonder if the 03 trucks came with a 5.9 and manual, in the 2500's?

 

That's what I was thinking, probably easiest to flash an auto instead of finding the needle in the haystack manual pcm. That being said you can buy a pcm on eBay and they'll flash your vin and everything in, I wonder if they can flash it to manual while they do that.

I have heard that the 03's had manuals with the 5.9's, but I doubt they'll be much easier to find.

Do you know if the wiring harness from the manual and the auto the same? Or modifiable to be the same, cuz if they are it might be easiest to find an auto one, pull the motor and wiring, then get one of the eBay pcm's.

 

There are going to be some differences. The PCM runs the auto trans, so there will be wiring for that purpose, that a manual trans truck simply won't use. I suspect you could just remove it, and call it a day. (would have to do something for the neutral safety switch though, park/neutral switch on the trans..... probably just jumper the connector, and call it a day.) I am not sure if there is anything on the manual trans that the PCM actually pays attention to. Not like there is a VSS on the trans any more.....) All the engine connectors will likely be exactly the same as well, except, perhaps, the crankshaft position sensor..... I know they are different lengths on the 2nd gens.... (but, so far as I know, the connectors are the same? not sure, haven't had to deal with it. )

 

That year (through 03) a separate TCM runs the auto trans, so theoretically (if it were available) you could flash a manual trans program into it and call it a day.

 

Sorry for the late response, Work has been busy. So I should be able to flash an auto PCM to manual, but it still needs to be a 3rd gen because of the difference in the Bus. Do you know if the wiring harness is different between the 2nd and 3rd gen?