On my way to work today, I heard a distinct whistling sound coming from the engine compartment, and I instantly feared my plenum gasket had failed (again). When I got to work, I pulled the PCV hose and capped it off, and then checked for vacuum in the breather hose to the air filter housing and confirmed that the plenum gasket is toast. This is the 3rd time it's gone bad (second time with the Hughes aluminum plate), and I'm over it. If I'm going to do anything about it, I'm going to replace the stock intake manifold with the Hughes one-piece manifold.

However, given that my truck has over 212,000 miles on it, I'm certain the stock heads are also toast. The last time I checked compression, it wasn't all that pretty. So I'm thinking some new heads are in order, too, and if I'm going to do that, some new headers, as well. This is venturing way out of my league, though.

So, I'm curious what else I'd need to consider replacing in addition to the intake, cylinder heads, and headers. Can I just bolt on the new heads and re-use the stock cam and all other internals? Or, maybe I should ask - would it be a terrible idea to just bolt on the new heads without changing anything else internally? Would I also need a new tune to pair with the new heads?

Sorry for asking so many novice questions, but this is far beyond the scope of anything I've ever attempted before. I appreciate any input I can get. Thanks!

Edit: It looks like my signature (with truck specs) no longer shows up, so here goes: 2001 Ram 1500 4WD with 5.9L/360 engine, all stock. 212,000+ miles, 3.55 gears, 285/75R16 BFG KO2 tires.

 

Have you changed your timing set yet?

Given the mileage on your truck, think I might be tempted to just put a long block in it. Put the hughes intake, and some decent headers on it, and you would be all set. Basically, it just depends on how much you want to spend.... You *could* just toss some new heads in there, but then you still have a high-mileage bottom end......

 

Thanks for the reply, HeyYou! I forgot to mention that the timing chain and water pump were replaced about 30,000 miles ago...so not necessarily due for a replacement. As for the budget...therein lies my conundrum. As much as I love this truck, I really can't justify sinking a bunch of money into it. I also have a fairly low-mileage '08 that is in excellent shape, so it's not like I NEED to fix up the '01 to make it dependable. I also have too many other things I need to spend money on right now to justify putting a large amount of money into a new engine for this truck. Plus, if I soup up the engine, what next? New transmission? I can see myself chasing this truck down into a deep, expensive rabbit hole if I'm not careful.

So I am conflicted. As you said, if I bolt on some new heads, I'm still left with a high mileage bottom end. Based on everything I've read, sinking money into repairing the stock heads makes no sense because it removes material from the already-too-thin deck, correct? So I'm really not sure what to do at this point. By the time I buy new heads, a Hughes airgap intake, and possibly a cam, I feel like I'm 50% of the way to the cost of a crate motor...so maybe you are onto something with a long block.

I'm not really looking for any huge performance upgrades, though I would certainly welcome a bit more horsepower. But this is strictly a work truck, so I have no desire/need for crazy horsepower/high RPMs, and I'm fine with the low end power band. But if I can spend a little bit of money and make it reliable for some years to come, while maybe also increasing power/economy a little bit (as I've read the Hughes intake will do), then I'm all for it.

Sorry...I'm talking in circles now. Thanks again for your feedback!

 

Maybe a mopar crate motor?? Bit of a power boost, but then you would need a tune to go with it. (another 500 bucks or so.) Wouldn't need to worry about the engine for the foreseeable future. Address the other stuff when/if it becomes necessary.

 

The Hughes one has lasted in my truck for 10 years(or more forgot when i did it) with no issues. You need to use the fel pro gaskets(not the crap that Hughes sends with the kit). If i remember correctly the bolts they send you are too long also. Got the right size bolts used lock tight and lock washers and it will last the life of the truck. If you get air gap it will kill some of the low end power.

 

Yeah, I used a Fel Pro gasket both times. The first time it failed after the repair, the plenum bolts were barely finger tight when I removed the intake. I hadn't used loctite on them, because the bolts that came with the kit already had thread locker on them. Apparently that was the reason for the failure. The second time, I made sure to add loctite. This repair lasted longer, but still only about 4 years. I'm beginning to suspect my torque wrench isn't calibrated properly.

Part of me is tempted to try the repair again and simply use RTV instead of the plenum gasket. Has anybody here tried that?

 

That's bad luck. My Hughes kit has worked perfect since about 2006 and some 150k. It's the cure kit so may the keg is warped or something. Grab a keg from the junkyard and weld the plate on this time.

 

Use lock washers along with the lock tight. This way you have two things keeping the bolt in place. You could have the plate welded to the intake then you would have a "one piece intake".