20/22 Exhaust studs/nuts...
I will NOT use the factory exhaust manifold locking nuts.
http://board.marlincrawler.com/index.php?topic=100729.0;message=1125437Although the guys at 22RE Performance are very knowledgeable and sell very high quality parts.....their comments on their site that the exhaust studs in the head get brittle, and sell the stock-looking locking nuts, is somewhat misleading. If you should attempt to remove the studs from an old head, you will most likely destroy the threads in the alloy head, then you will need to tap and heli-coil the threads in the head.
In my experience the brittle studs have nothing to do with the issue with exhaust manifold or header leaking at the gasket. The factory style locking nuts' clamping pressure will cause the studs to spin inside the head when attempting to torque or loosen the nuts on the studs, then you cannot get the header or exhaust manifold tight enough against the gasket and header..... you get that very irritating exhaust leak!
From 22RE Performance site...
Quote:
Due to the countless number of heat cycles yours have been through, it makes the studs incredibly brittle. When you try to remove yours, you’ll pull most of the aluminum from the thread holes along with them. The last thing you need when installing a new engine is to break a stud during install. Take our word for it, you don’t want try to re-use yours. Our kit includes all 8 OE studs and 8 OE self locking nuts and 2 OE bolts for the air injection / block-off plate at the upper exhaust manifold. $55.00 for the kit. Unquote
That's just my opinion - it may be worthless.
Gnarls.
