Intake gasket woes.....any suggestions?

[jim_howard_pdx]

I am using Felpro perma seal gaskets for ported heads. The block was squared and the heads were surfaced. The gap is straight and regular. I use only RTV at the valley NO CORK for this racer.

The gaskets seal fine for many months. But the aluminum heads walk the iron block (this is normal) and the heads and the intake grow as they heat, and shrink as they cool every time I run the car. After about a year, the felpros litterly shred. They are torn to pieces. I have shown these to my racer friends and they are all amazed. Each thinks it is an intake manifold torque issue, but now that I see the chevy guys are demanding specialized intake gaskets to eliminate this problem I see it as an aluminum issue, not a machining/torque issue.

I am wondering if anyone has tried using dead soft aluminum or copper intake gaskets instead of the rubberized paper felpros?