.. how healthy/unhealthy my engine is. I honestly thought things were going to be worse on this trip.

I normally get to drive the truck about 10-20 min at most, in the city, flat ground, to and from work mostly.. no freeway just 45mph limits.

Yesterday I drove over two hours at highway speeds (55-70mph limit), with some decent inclines, and over 850lbs in the bed/cab including myself.

I was able to get around 70-72mph uphill at ~1850rpm in OD without too much pedal input when speed was limited to 70mph. I felt I could have pushed to 75+ with minimal effort.. and once reached 75 not paying attention.

If the posted limited was 55mph(doing 55-60ish mph) I had to drop out of OD to maintain speed on the hills (does this sound like stock gears with 33"?).

In the afternoon I spent about an hour on the sand air'd down to 18psi and following a LS1 jeep cj with same tires and much lower pressure(nothing crazy, just cruising around smaller dunes and dune outskirts).

I am pretty sure the plenum is leaking, and the cap and rotor Im sure are very old, along with the timing chain(~162K now). I just recently changed plugs and wires ( https://dodgeforum.com/forum/2nd-gen...today-656.html ) which were in pretty bad shape.

Any thoughts?.. Is this normal for a truck with bad plenum and possible other problems? Was also worried about clogged cat and possible cracked heads? Any idea if this is stock gearing or not?

Gotta say was the most fun day I have had with truck.

Thanks for any feedback guys.

 

Yeah, that sounds pretty typical for blown plenum, and stretched out timing chain. Do the cap and rotor when you do the plenum/chain. (and water pump...) You will be amazed at how much power you pick back up. 33's and 3.55's ain't helpin' ya none either.

 

Sounds pretty normal for 3.55s and 33s. When you're going faster and the rpm's are higher the engine is making more power/torque so it doesn't have to drop a gear.

 

Yep, sounds normal to me to have to drop out of O/D on grades at 55MPH with 33's on the ground.

At 162,000 miles you're due for a timing chain, and if you're not sure of the age of the cap and rotor it'd be best to just swap 'em out so you can be sure from here on out. Plug in a fresh new PCV valve from the dealership, too. Regarding the plenum, if it were mine I'd do the test from the TSB and act (or not) according to the results.

 

I'm sorry, but I disagree with the useless TSB test, Unless the gasket is really blown badly. I have first hand experience with that useless test on my 98 and numerous other peoples motors. The only real way to know is to remove the TB and look with a small mirror and flashlight.