94,
As John mentioned, I've got a set of Brodix 18X's. Check out the Brodix website for flow numbers on the standard version and the M2 CNC version.
There is more in them even over the CNC version, but it takes quite a LOT of work. Probably in the neighborhood of 80+ hours porting and 3 flow bench sessions. Not to mention I had a GREAT deal of guidance from one of the premier Pro Stock head porters in the country.
I should get the heads back from a fresh valve job and resulting flow numbers on Tues. and I can give you the final flow numbers. Final runner volume is in the 256-258 cc range. I need to remeasure when I get them back. You can see some of my home port job and engine details on my website:
http://hometown.aol.com/jgchevelle/engine.html
It will likely be several months before I get the engine on the dyno as I'm in the middle of moving and my wife has PLENTY of projects that I've been told take priority over finishing the engine. It is KILLING me knowing I have everything except the pushrods to complete the engine and no time to work on it. I'm shooting for between 730-750 honest HP @ 6800 RPM and around 640 lb-ft TQ.
In general, the 18X fall right in the middle of a 23 degree head and a true 18. A good 18 degree head is about 100 HP better than a 23 degree head. The 18X's are about 50 HP better than a 23 head. Again these are generalizations.
If I had to do it again, I would pony up and just buy a set of std. 18 degree heads and the shaft rockers that go with them. The pushrod restriction really holds the 18X head back. It is what it is.....a compromise.
