Quote:

I believe that pretty much any type EXCEPT the chrome ones will easily seal.
Years ago before I heard about all the problems with them, I got a chrome Mopar Performance neck through the local Dodge dealer.
Tried everything - double gaskets, homemade gaskets, washers for the bolts, different torque values - no joy.
You can actually see the curve in the mounting surface after installing/removing.
They are just made with very soft metal and distort very easily.



Exactly...
The chrome one has a thick base and distorts when hot...
Made in China out of recycled Coors cans, Mopar, Summit, Jegs, PAW and many auto stores including Oreily sold them..
I tried all the mentioned things...
Higher torque down
Sanding its base
Double gasket
No gasket w/RTV
High temp sealant

IMHO...
The root issue, is its material simply distorts after getting hot. Got the Napa one, installed new gasket, torqued it down...
No leaks 3 years later..

Just my $0.02...