Like the title says, I need advice on what I can do to get more power out of my 02 Ram 1500 5.9L 4x4 (quad cab,longbed). I usually tow around 5000lbs, not including the trailer. There's somewhat steep grades on the highways where I live and my truck struggles to stay at 55mph. My brother's 04 Silverado 1500 5.3L handles those steep grades at 65mph no problem.

Any advice will be appreciated.

 

Gears would be your best bet.

 

Agreed, gears are your best bet. 4.10's at least.

 

i'm gonna third that notion.... had a 2000 ram 2500 with stock 5.9 5speed and 4.56 gears and that thing would pull a house down lol

 

That's funny because my '98 RCSB 4x4 5.9 gasser would tow circles around my '02 Chevy Z71 QCSB 1500 5.3.

I would suspect a couple of things:

1) Is your plenum gasket 100% intact? A leaky plenum (VERY common) robs a lot of power and usually a good bit of fuel economy.

2) Is it properly tuned up?

3) And this is a biggie - GEARING. My '98 had 3.92 gears as opposed to the standard 3.55s that many 2nd & 3rd Gens shipped with. IMO the tow package should automatically come with the taller gearing, but it doesn't and if the dealer ordering the vehicle didn't spec 3.92s then you got 3.55s.
My Chevy had 3.73s which would make for better towing than 3.55s, but not as good as 3.92s.

Also, to be fair, you are comparing an engine that basically was designed in the late 1960s and only slightly upgraded through the years (fuel injection, aluminum heads, etc.) to an engine designed in the late 1990s.
Despite having less displacement, the 5.3 (which is nothing more than a 9mm stroked out 4.8 V8 BTW) puts out 290 HP and 315 TQ, or as much as 315 HP & 335 TQ if it's an '04.5 (mid model year upgrade) or newer. By comparison the much older technology LA360 (5.9L) puts out 230 HP although it's large displacement does make 330 TQ.
At very low RPM you would probably be right there with your brother as low end torque is pretty close, but once you get into the mid RPM powerband then his 300'ish HP is going to outpull your 230 HP. Not to mention you have a technologically ancient transmission (the 45 & 545rfe that replaced your 46re is light years more efficient and doesn't have near the parasitic loss from crank to rear wheels). Again, he has a transmission that was basically designed for the newer GM 4.8 & 5.3 engines at the same time period.
Simply from a technology standpoint - he's got it all over you!
Another thing I would bet is that his aluminum engine truck is WAY lighter than your cast blocked, long bed, QC truck weighs.

Check your plenum (many how to's on this forum - especially in the 2nd Gen section as you own a one year holdover 2nd Gen engine in a 3rd Gen body).

Two things I can suggest. Regear the truck to at least 4.10 gears, 4.56s if you are running larger than stock tires. Normally I suggest the jump right to 4.56s in 3rd Gens but the 545rfe basically has two overdrive gears and won't lose highway fuel economy but a four speed will. If power is more important to you than highway gas mileage then by all means go to 4.56 gearing.
Other thing I'd do is invest in an aftermarket tuner. The 5.9 mainly as a band aid for the plenum gasket issue was DE-TUNED dramatically at the factory. A Superchips tuner will add close to 50 HP and 50 TQ to your engine - but if your plenum gasket isn't blown now, the added HP will probably blow it - so do a Hughes Plenum kit as a permanent fix (retail $125 but I've seen it on ebay for under $70). I just installed one for a friend on his 5.2 V8 Dakota and it took me about 2 1/2 hours in his driveway. Immediate power gains and in the three weeks since I've done it he's reporting a 4 MPG fuel economy bump.

Hope this helps...

 

Hammer pretty much said it all... an easy way to see if you need the plenum fix is to look down inside your throttle body and see if there is any pooling or oil residue in there. it's a 5.9 with probably a considerable amount of miles on it so there will be lol. also, another problem they had were the timing chains. they tended to stretch so getting a double geared timing chain wouldn't hurt. i put a programmer on mine and it really woke it up, but i would check the deficiencies first. good luck. o, and one last thing f@*k chevy...... that is all

 

I should also add that we/I'm not bashing your engine in ANY way. Like all engines, it has a couple of shortcomings, all of which can be overcome quite easily with after-market parts/modifications.

There is a reason this engine lasted in production for 35 years. It, and it's 318 CI (5.2L) brother, are basically tanks and have shown that with even marginal care they can last for years and sustain relatively high mileage. The other advantage is that because of how long they existed, aftermarket parts are plenty. Hell you can even buy stroker kits to bring them up over current Hemi HP & TQ numbers.

I wouldn't be surprised if 20 years from now there are more LAs on the road than the 4.7s and Hemi engines that replaced them. I'm currently about to start a total rebuild on the 4.7 in my Grand Cherokee, which dropped a valve due to a **** poor design flaw and this is with only 102k on the ticker and meticulous care!

You can go a lot farther with this engine with power adders, but the plenum kit, gears and the tuner should bring you up with and even surpass your brother's Chevy when it comes to towing...

 

Hey I have 5.9 also and love it and like Hammer said just add mods and you will be amazed but I just installed the SuperChips tuner and I see a small gain in power but nothing worth being amazed about also our 2002s don't get the advanced Trans tune

 

I was doing re-search on the SC as well. They say there is no H.P. gain with the tow tune. Trans shift point changes only. They also said you should not use the performance tune to tow. Something about pinging. So not sure if I want to spent $300 just to change shift points. did the gears last year (love them). I am gonna lose the pwr wire, and do the 180 T-stat. just my 2 cents.

 

You're comparing apples to oranges, the 5.9 (at least the ones that were "death flashed" at the factory) are greatly de-tuned compared to the Hemi and 4.7, so the gains are huge by comparison.

Also, I wish to hell I dyno'd my truck with the tow tune when I had free access to a dyno, but I never even gave it a thought because I've read where the gains are almost the same with the tow tune as the performance tune, only difference being that timing is advanced a lot more with the perf tune. I also heard what you are saying - that there are no HP gains with the tow tune - just low end torque gains, firmer transmission pressure and optimized shift points. Problem is - I've heard both from Superchips employees. So I really don't know what the tow tune does. I will say I've used it and it does pull better'n stock...