so help with cat exhaust manifold restrictors

the new gaskets from BD work great , there are no sleeves in them as per the old ones, atleast you will not have to worry about a sleeve breaking and taking out the exhaust wheel! install & enjoy.

 

throw them out and enjoy i did a couple cats without t he sleeves never had a problem

 

Scrap the old sleeves, not counting the higher flow manifold you just bought, when the sleeves are left out it's another 30 crank horsepower.

 

I have a question only because I was told they were to dissipate the heat to keep studs from breaking have you seen better results for this or about the same?

 

The only way to keep the studs from breaking while in service is to spend some extra money and buy the stainless spacers, studs and nuts. I'd still put anti-seize on them.

 

Cat tried stainless fasteners and they went back to the normal ones, they both break so at least you can drill the standard studs and get them out when they do break, the stainless studs just make that job harder than it already is.

Studs break because the pressure in the manifold is constantly pushing the end pieces away from the center, once the end pieces move far enough they put side pressure on the studs and then they break.

The sleeves are there to insulate the head from the exhaust temperature, they keep the heat soak to a minimum, but it is not an issue to run without them.

 

http://www.thetruckersreport.com/tr...ding-a-6nz-any-suggestions-3.html#post2528246

I posted pics in this thread of a stud kit that was r&d with ARP. You will not break one of these. ARP wont sell direct, so if there's interest pm me.

 

I noticed the PDI manifold how much difference do they really make

 

They don't leak! You may see a slight mileage improvement but the ROI will be a long time if that's your only reason. But if yours is leaking I would not hesitate to buy one.