Thanks for the the info. I've read it steals a fair bit of power even more so at higher levels.
These are smogger #416 casting GM heads I'm working on.
Here's a photo of exactly what I'm talking about so there's no confusion. This was taken before the final blending of the sweeper cut in the bowl. My plans are to fill the cross over all the way to the exhaust bowl and blend it in. With the stainless plate idea are you wanting to weld it in the exhaust port or are we talking about different things?
Stuffing it full of aluminum foil isn't a bad idea. I guess the only problem then would be figuring out how to keep it in there and uniform in the exhaust port.
I was wanting to try block filler, some say it works great and with a gallon costing $15 it's very appealing.
F1Fever you used quick steel for this? Just wanted to make sure we're talking about the same "part" of the head I know some confuse it. I tested Quicksteel out just to see how it handled it's self under extreme heat and it get's hard as nails held over a flame, not brittle or flaky. But I don't know how it handles it's self over time, or adhears at those temps, ect.
Thanks again all