CLASS RACER FORUM - View Single Post

Adger Smith · 12-01-2019, 01:02 PM

I have been told that all the X castings were built from core boxes that were marked X because they were out of spec and were to be destroyed.
Apparently the upper part of the mold on the long side by the valve guide was built big or worn out of spec. Most of the X heads I have handled since the mid to late 60's( passed through my shop) were in the 10 CC bigger range. If you do a mold of the original ports it is very apparent where the extra CC's are. They are still sought after by Dirt track customers.

12-01-2019, 01:02 PM	#11
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: 1966 327/275 cyl head cc I have been told that all the X castings were built from core boxes that were marked X because they were out of spec and were to be destroyed. Apparently the upper part of the mold on the long side by the valve guide was built big or worn out of spec. Most of the X heads I have handled since the mid to late 60's( passed through my shop) were in the 10 CC bigger range. If you do a mold of the original ports it is very apparent where the extra CC's are. They are still sought after by Dirt track customers. __________________ Adger Smith (Former SS)