440Source "Stealth" heads, your experiences and opinions
I have experience with them and it has been 99% positive. A mild 440 can make 475hp pretty easily on pump gas with 9.5:1, 750cfm carb and headers.
Three thungs I do before running them (specific to these heads):
1) Use a rotary file to improve oil drainback, especially around the spring pockets. This will help avoid seepy valve covers.
2) Install thread inserts in the valve cover bolt holes.
3) Use a *minimum* of a 4.410" bore head gasket to avoid the fire ring overhanging the chamber.