ill informed my friend. If you just weld onto it, yes it will crack. If you use the proper rod, pre heat, maintain heat, and post heat and wrap... I'm not worried. My buddy(tig instructor @ a local university) is welding the cast piece.

thank you, come again.

 

Ooh im liking this project Any more info on the setup?

 

just because you have heard of cast cracking when welded doesnt mean they did it correctly. there is a way of correctly welding pretty much every metal.

 

cast likes to crack because 2 different metals, 2 different heat cycle expansions, and one similar weld holding them together.

 

that and what affects the hardness of metal is the carbon content and cast iron has a lot and by heating it up while welding makes the metal very hard and hardness=brittle and just cracks when it is heated up becuase some expands a lot less then the other part of the same piece of metal.

 

Check my first post. I did some editing. Added some more pics aswell of the car.

 

Your chevelle is ------- sweet.

 

haha thanks. Its a bit rough, but fixing the rust and scratches doesn't make it faster I also tossed a couple pics up from this year with the C5 Z06 wheels on it.

 

Normally I don't like new looking wheels on old muscle cars but the Z06 wheels look bad-***.

 

The headers will be fine, especially if you bevel the welded edges like you're doing, then fill the bevel in with weld. That's how I did my cast pipe fitting log.