Head CC ?

Chipper Chapman · 04-19-2013, 09:26 PM

In a conversation with a friend, he mentioned his late 70's 350 stocker is allowed to have a 624 head, milled to 63.3 cc. I questioned how it is that the spec is so small for a head always known as a 76cc smog head? So I got looking around, the same exact head is only allowed to be 73.7 cc on an 86 truck 350, which is far more realistic. GM only made the one 462624 casting (excluding the newer hecho en mexico) So does anyone know why such a large difference?

04-19-2013, 09:26 PM	#1
Chipper Chapman Member Join Date: Jan 2004 Location: Belmont N.S. Canada Posts: 473 Likes: 246 Liked 166 Times in 71 Posts	Head CC ? In a conversation with a friend, he mentioned his late 70's 350 stocker is allowed to have a 624 head, milled to 63.3 cc. I questioned how it is that the spec is so small for a head always known as a 76cc smog head? So I got looking around, the same exact head is only allowed to be 73.7 cc on an 86 truck 350, which is far more realistic. GM only made the one 462624 casting (excluding the newer hecho en mexico) So does anyone know why such a large difference?