what is your opinion this combo?

Make these changes:

1. get a thicker Cometic metal shim head gasket.
2. get a better cam. Call http://www.hughesengines.com/ and ask them for the best cam for your setup.
3. Get an Edelbrock performer RPM air-gap.
You should be able to hit 425 HP easy with a mild HEH1928AL cam.