thinner head gasket for 390

[XR7]

How can the Edelbrock head chamber be 4.160 wide? I'm confused.

Because that is what they measure out of the box, on bare or assembled heads, when they machine the chambers for the seats, the outer walls are cut at the same time or just part of the normal machining process. That is before the valve job, if there was any "un-shrouding" done... it will be even wider. Your chamber is wider than your bore, you will see when you take it apart. Having said that... there are plenty of 390's running hard with Edelbrock heads.

You have pretty big valves for a 4.050 bore... I was thinking your bore was 4.080. I am guessing your exhaust valve is very close to clipping the bore.

I did not use sealer when I first put it together, all decks were fresh machined and smooth, Cometic doesn't recommend sealer. I have re-used Cometic's on the same engine before, then I do use copper coat before assembly after I have cleaned everything up, as best I can. No problems sealing to date. In your case... I would most certainly use it.

[rcodecj]

As far as Cometic head gaskets go I am changing course and just going to go with the Felpro 1020.
It won't run as good, but it'll run a bit better than it did and hopefully not leak.
This shortblock and the iron heads that were on it are going to a friend anyway.
I can live with it as is until I build the other motor (428)
Sometimes I sweat the details too much, but that's part of the fun.

Thanks for the help guys.

[rcodecj]

You have pretty big valves for a 4.050 bore... I was thinking your bore was 4.080. I am guessing your exhaust valve is very close to clipping the bore.

I wanted to make a correction so people don't go out and use 1.71 valves on a stock bore 390 base on my comment.
My exhaust valves are 1.66.
Sorry for the confusion.