Originally Posted by bigblok86ranger
Scotty I hope you don't mind but with all the questions about these heads I had decided to make a sticky so all can have informed info, after working on a new thread (then abandoning it) I decided to Stick this thread as there is a ton of useful facts in here.
This is a pretty old thread. I have since discovered much additional information about wet flow, intake port flow bias being incorrect, etc etc. I am going to need to transfer some of the information in other threads I have posted information on to this thread. The original positive feelings i had about these castings have been tempered by the quality of flow issues, odd wet flow characteristics and poor flow bias discovered in the poorly engineered intake port.
Peter Ken the owner of procomp whom I had spoken with on a number of occasions at the time I originally posted this had a chance to make a really good cylinder head however he did not.
I will add to this as time allows...
For all who read this remember:
The PC castings is a decent replacement casting in aluminum for the D3 head.
It is NOT a high performance head like the TFS street nor is it a replacement for said TFS street.
The casting itself is actually quite good though the valve job, cheap parts and poor assembly technique that procomp utilised make the assembled castings a no go in my opinion. Most of the ebay versions of these castings are crap in my opinion. They are cheaply assembled and misrepresented.
If Randy Malick, myself or others here outfit the castings with good parts, add a good valve job, do some minor port work and what not they are not a bad head for say under 550 HP applications however in fully ported max effort trim they are lucky to be 5% better than a max effort pair of D0VE's. Again this is a quality of intake flow issue.
I will and hope Randy will entertain reasonable questions about these castings in this thread. I will not put up with any unnecessary bashing, BS or trouble making here. With that being said I hope we can give an honest asessment of them and put this constant sore spot to rest...