Hey guys, I'm new to the boards and I just got a new (to me anyway) Ram.

It is a '98 model, QC 4x4 with the 5.9. It is stock except for larger tires (245s to 265s). It has just over 106k on the clock.I got pulled over on the way home with it for doing 85 in a 75 and the speedometer read 78 MPH when the radar detector went off. Anyway, the cop was cool and helet me off and told me I needed to get the speedometer calibrated. I verified that the speedometer is off by roughly 5 MPH when it reads 35 by driving next to my friend in his truck. His speedometer read 40.

I also noticed that it seems to lack power in OD and it will downshift on even the slightest little hill at interstate speeds. Would getting a programmer like Hypertech or something like that fix the speedometer/lack of power in OD problem it seems to have? I know a 4,500 pound truck isn't going to be aspowerful as the Z28 I traded for it but it almost feels like a V6 in OD at those speeds.

Another problem I noticed is that the driver's side door lock won't lock and unlock with the key fob or the switch on the door panel. It will lock and unlock manually though. maybe it is an actuator or something. Any ideas?

Now for power mods.

I've done a little bit of searching on these boards but I didn't come up with much in the way of stock rwhp/rwtq numbers. I know the stock factory rated numbers are 245hp/335tq but that is at the flywheel. Having owned a Z28, I know that performance mods are usually judged based on their rear wheel power production. That said, the only dyno numbers I saw were for a 2001 5.9 and it put down roughly 185 rwhp in stock trim.

I'm not looking to make the truck as fast as my Z28 was or anything like that but I would love to stay in OD up hills and pass people easily while pulling a bass boat without having to floor it too often. I'm thinking about getting long tube headers with an offroad setup since I don't have to worry about emissions, a cold air intake, and a computer program from a Hypertech or something like that. Would that meet my goals?

Sorry for the long post but Iwant to make sure I covered everything.

 

Get a circular intake, gibson headers, dual flows, high flow cat (or no cat, lol), autolite 3923's, fastman 52mm TB, and do the kegger mod (use search) and a new plenum kit from hughes or APS. That should put set you up pretty good.

 

OD just doesn't have much power. If you want to it have power it needs to shift out of overdrive. The Hypertech should however fix the speedo though.

 

I wish these trucks were 4500lbs... haha

Thats light!

More around mid to upper 5000's, even 6000's on some of the 1500s.

The scale at the scrap yard said my truck (4wd singlecab shortbox) was 5800 lbs... they are heavy trucks.

I would check your intake plennum gasket, if thats blown you will experience a lack of power... Ive never had any problems with needing to downshift at highway speeds up hills, unless I was pulling a trailer... so im guessing its somthing that can be worked out.

The larger tires can also affect the power... alot. How tall are the tires? just saying 265 doesnt really indicate the height...

 

Jr. Mechanic - Thanks for the suggestions but aren't the Gibsons shorty headers instead of long tubes? I know that long tubes made more power than shorties on the LS1 Camaros and Firebirds so I would think the same would hold true for our 5.9 engines. The reason I mentioned Pacesetter is because they were the only long tubes I found on Summit's site.

hometheaterman - I just find it shocking that when the truck is empty except for a full tank of gas and myself behind the wheel, it still has to downshift on very slight uphill grades. I can understand it downshifting up a significant hill but the hills I'm talking about should be a piece of cake for it. Let me put it this way, my friend's '97 GMC Z71 5.7 doesn't downshift on these hills. His truck is stock and is an extended cab model.

Sirhilton17 - WOW I had no idea these trucks were around 6,000 pounds. No wonder I'm feeling some withdrawal symptoms from my Camaro. The Camaro had right at 300 rwhp and it weighed 3,500 pounds. This truck has roughly 185 rwhp and it weighs 6,000 pounds.

Yeah, the downshifting is really irritating me because I would think that the truck by itself, without a trailer, could easily stay in OD up short hills. I'll check into the intake and see if there is anything wrong or not.

The stock tires that came on the truck were 245/75/16s and the tires that are on it now are 265/75/16s. I didn't think that would make a big difference on the highway but apparently it throws the speedometer off by 7-8 MPH somehow.

BTW, doesn't downshifting often harm these transmissions? I would just drive on the highway with it out of OD but then I get like 5 MPG LOL.

 

If you want it to downshift later, you can adjust the downshift cable on the TB. DO NOT BUY PACESETTER HEADERS! Every set I have seen has holes in them after a couple of years. Edelbrock or Gibson seem to be what most prefer for the 2nd gens.

 

Get lower gears if you want it to quit down shifting. If you're gonna stick with 265/75/16s get yourself some 4.10s. The ****ty factory 3.55 ratio is for like 225/75/16s

If you're thinking about getting bigger tires down the road, then you may want to hold off on this one, because it's not a job you want to do twice. But gears are the best bang for your buck, and if you're going to be towing, or if you plan on running bigger tires (like 35s) I deffinetly reccomend it.

 

Are you guessing at the rwhp or did you put it on a dyno?

Look around the motor compartment and on your pcm for a DC issuedsticker that says something about an authorized software update. You may want to get yourself a tuner. I recommend aSCT tuner. They are more expensive to start with, but as you mod it gives you the ability to flash updated tunes that you recieve via email.


You are on the right track with the lt's. Iran shorties, and am now running long tubes. The long tubes are better by leaps and bounds.

My truck weighs ~5250 with me sitting in it, as weighed by the scales at a major food distributor andDOT scales. DOT was actually around 5270

 

Pacesetterpainted shorties had a bad rep there for a while, but so far I have been very pleased with the ceramic coating on thelt's.IIRC it's been maybe 7 mos. and they still look like they did the day I installed them.

A word of warning though; If you go with the Pacesetters and they send you those white chknsht gaskets, throw them away. Get yourself somemetallic ones. I used theFelpro when I had to replace mine. They were cheap and have held up good. There are some more expensive options out there (copper) if you want the added peace of mind.

 

Cool, thanks for the tips. I guess I'll go with the shorties instead of the LTs.