I respectfully Disagree for the sake of this arguement. Have you ever seen anyone mention a stock plenum plate that has cracked or developed physical failure in an engine? I believe in this application the fatigue issues you mention are a moot point... unless there's some serious pressure being pushed on it and in that case most would have swapped the whole intake with an improved Higher power design.
if properly sandwiched there is plenty of force to hold the gasket in place without problems...
I guess I'll just Agree to disagree here and let the facts speak for themselves... Which is all I was asking for in the first place.

 

I definitely didn't get the Hughes plate for "cosmetic reasons"...hell, who besides me would ever know it is there. I did, however, feel that the "safeguard" for whatever causes the failure far outweighed the solid day of work it took to get to the stupid thing. I just wanted to fix my truck, but since it was so labor intensive I have replaced everything along the way...and of course threw in some cast aluminum and Hemi orange paint

I don't really care what fixes it...the plate or the bolts that come with it or the gasket. I have the motor busted wide open so I did what seemed right by several standards. I agree that the dis-similar metal thing sounds a bit far fetched when aluminum and steel have been used together forever.

All that being said, I'm glad I finally took the time to tear it down. It's been bugging me for a while and it was worth the experience if nothing else...plus I got to buy a few new tools. What else was I supposed to do with 2 1/2 weeks off work

 

any takers on the timing chain question?

Is there an advantage to the double roller other than longevity? Seems to me it's all just banding two gears together.

 

From everything I've read roller lasts longer and performs better but is not used in oem applcations in most cases mainly because of cost... Non double roller can also leave nylon pieces when it degrades so I've read. but the non double roller type will stretch less...so thats a big plus for it.

 

There are some fairly steep pressure changes in the intake. I wasn't really as concerned about cracking.... (as yes, that would take a LONG time.... the engine may not even LAST that long...) but more about the flexing displacing the gasket over time.

Torque values on the bolts aren't really all that much, what? 84 inch pounds? but, having a thicker plate to distribute that force more evenly over the sealing surface just seems like a good idea to me. Call it "cheap insurance". I have yet to see an aluminum plate fail, that wasn't due to installation error. Granted, we haven't seen a steel plate fail after gasket replacement either, but, that's mainly because 99% of them we hear about, replace the belly pan...... There were a couple folks recently that were doing the shorter bolts/better gasket/steel pan route, but, so far, haven't heard back from any of them one way or the other. Not that I would expect to for several YEARS after the repair........ unless of course, we had a case of installation error, and it failed fairly quickly.

In the end, is the aluminum plate NECESSARY? Probably not. Is it a 'good idea'? Yeah, I'd give it that.

Double roller timing chain is more accurate, stretches less, lasts longer. A win-win-win upgrade.

 

I will say that I love the 3.9 V6 in mine. If you find the engine is caput & decide to swap for a V8, message me to sell the upgrade parts if you no longer want them. As for the double roller, I know that I do not always feel great about the timing in mine. I have seen many threads here about the double roller cleaning up timing issues in a more worn engine.

 

got her all buttoned back up, here's a few pics before I bolted all of the ugly crap back on and covered it all up...

 

got it cranked back up...ran pretty rough so I reset the PCM and now it's running fine. Had a pretty noticeable knocking coming from what sounded like the lower end...never heard it do that before. Took it for a spin around the neighborhood and the knocking stopped. Maybe things just needed to get lubed back up but it sounded suspicously like a rod bearing.

Still gonna seafoam it tomorrow and replace all fluids.

I've got a question about the vac line from the brake booster. Does any fluid run through the booster from the master cylinder? The reason I ask is that I'm wondering if some of the crap that was sucked into the intake could be coming from there. I tend to think not, but I don't really know what goes on inside the booster.

 

Shiny!

About how long would you say it took from start to finish? I'm thinkin about starting this tomorrow.

 

I took my time and had to wait on parts, paint to dry, etc...took me 3 days. That was; plenum plate, valve covers/gaskets, timing chain, water pump. Cleaning everything took the longest. If you dont want to paint you could do it way quicker but getting that stuff clean enough for paint is a bitch. Reassembly went smooth, trying to remember the routing and which brackets shared which bolts was a bit time consuming. I probably installed the accessory stuff at least twice.