I've said it a hundred times (or more); I doubt Dodge actually had engineers working for them in the 90s. The later Gen 2 intakes resemble the kegger mod. If you are looking for low end torque, I don't think it helps much but it does for high end.
If budget is no object and you have the time and plan to keep the truck a while: replace plugs, wire, cap, rotor, thermostat, coolant, all hoses, belt, idler pulley, cracked/brittle vacuum lines, PCV, air cleaner, oil and filter, all the sensors in the throttle body and intake (low on the prority list), O2 sesnors, catyltic converter, timing chain, water pump, do the sea foam treatment, reset the PCM. That ought to keep you busy.

 

I plan on doing the plenum pretty soon here...

I'm doing the plenum/gasket, the intake gasket/bolts, timing chain and sprocket, a thermostat (should I go 180 or 195?), and finally an oil change.

Then my next project is bodywork..oh boy.

 

Well I'm done. Would you fellas believe me if I told you my OEM plenum gasket wasn't blown? Well it wasn't! There was no oil in the intake either! I'm glad I did the replacement though, I won't have to worry about it. It also gave me a great chance to replace some parts, like the coolant sensors, thermostat with the Hypertech 180*, coolant, gaskets.

 

Is it necessary to replace the coolant AND oil? do the coolant sensors actually go bad or was it just "while you were there"?

 

You should replace the coolanat every two years. When you pull the intake, contaminates can get into both the oil and the coolant. Sensors do go bad but they generally last a long time. I replaced the cheaper one while i was in there.
So, absolutely replace oil. I strongly recommend replacing the coolant. If you have the time and money, do the sensors.

 

where is the plenum at and if you replace it do you get more power

 

Mopar360: we HIGHLY suggest that you read through the 2nd Gen FAQ first, BUT, to answer your question quickly, the plenum plate is mounted to the bottom of the intake manifold. The only reason we are removing it is to replace the gasket on it, which blows often in our Dodge trucks. It will only get you more power if it was blown and you're engine was sucking oil into the combustion chamber.

 

The plate they are talking about is on the bottom of the intake manifold. If the gasket between the plate and the intake body is blown, you'll have more power if you fix it and you won't burn as much oil. If it's not blown, it's not going to get you more power by replacing it.
The generally accepted thinking is if you have a Magnum Engine and it is pinging alot under load and it's burning oil, the plunum is blown. You can verify by pulling the air cleaner and looking down into the throttle body with a flashlight. If you see oil, it's probably blown.
There's some debate if the reason for the gasket failer is:
-the plate is steel and the manifold is aluminium and they expand at different rates when heated
-the bolts that hold the plate on are too long
-the gasket just wears out
You have to pull the intake manifold to fix it. There's more debate on the best way to fix it. You can use something called the Hughes kit, you can get a new air gap manifold, you can just clean it up and use a felpro gasket, or you can make a plate out of a sheet of aluminum yourself.
Search "Hughes" and "Plenum". This should give you enough background to make sense of what you find.

 

thanks for the info