Do any of the senior Jeepers know if there has been a part number change for the 07-11 3.8L Manifolds.

I am wondering if over the last few years, Chrysler has tweak the pour mixture on the casting metal of the manifolds to get better long term durability. A part number change might indicate this. Or they may have tweaked it without a part number change to avoid ridicule.

I'm aware of the problems and benefits with both

Headers = $650 - Heat, won't stay tight.

Manifolds - $70 - Eventually crack, I got 5yrs out of mine.

What would you go with???

PS I am 99% sure mine are cracked, just haven't pulled the heat shield to confirm.

 

The key to keeping headers tight is proper fastener and proper torque with a good quality gasket. There are several high quality gaskets on the market that will do just fine. there are a lot of European cars that run a header style manifold or headers directly from the factory and have no issues what so ever. Torque your bolts in in steps to get to the final torque needed for proper clamping.

As far as a replacement manifold I have no clue but there may be someone after market making one with a slightly different casting that would have more durability Dorman is one company that would come to mind.

 

Thanks, what gasket manufacture would you recommend?

Or material?

I have access to a lot of shop/manufacturing equipment so I could draft something and have it made if it was worth it.

 

OEM manifold (LEFT side) part number is now at 04666024AD...so there have been a few revisions.

I have read nothing but horror stories of guys switching over to a header. They seem to get too hot and melt stuff.

 

I kinda figured this might be the case with the part number change....I might run a pair of OEMs again and see if they hold up.

If I was at my old job I could have the old and new manifolds spectrometer tested and see if they increased the molybdenum content. I kinda wanna bet they did!!

 

I have a leaky bank as well. I think my sudden mpg drop is also to blame. Anyone every ported out a stock manifold? Lol

 

I was considering porting a set out. I think the gain will be minimal, but why not at least clean up the edges and match it to the gasket.

 

To combat the headers radiating to much heat ceramic coated headers are designed to hold more heat inside the header and help with velocity of the exhaust gasses. The other way to combat heat with a wrap to hold the heat in and help as the ceramic coating does. The added charge of the ceramic coating is not just there because they look prettier it also aids in the function of the header.

Percy's makes soft alu ones but I am sure you could find a quality set of Copper which is what I recommend for exhaust applications. If going back with stock type multi layer gaskets I personally prefer Victor Reinz gaskets. It seems they tend to have better quality control then Fel Pro does any more these days.