crazy, never seen them. im guessing during normal operation just the primary is going, then when u slam it the 2 secondaries open?

 

Holley , I had one on my 428 and yes they had more than a 950 3 barrle, there also was a 1050.



[IMG]local://upfiles/58274/D439EBECCD1944FE80E60A7820A96499.jpg[/IMG]

 

Original Cleveland heads only came in the 2 and 4 valve variety. The 3 valve is an aftermarket cast iron head and was developed for those tracks that don't allow aluminum heads.

 

Sor
Clevland never made a 3 or 4valve head. Unless it was some aftermarket thing with a double rocker arm for two valve operation with one lob of the cam.
The 302 boss had a clevland head, 2 valve
the 351 2barrel and 4 barrel had 2 valves per cylinder
the 351 boss had 2 valves per cylinder and the 351/400 M had2 valves per cylinder