12G1316 head vs. 12G940

[gatsby989]

Can anyone please help me understand the difference between these two heads?

Thanks!

[Alex'n'Ane]

For all intensive purposes nothing. They have I believe extra air holes or similar for the exhaust ports. And according to the bible they are thicker around the exhaust ports, so allow for marginally better shaping. But in essence nothing worthwhile or significantly different.

[bmcecosse]

That's the Austin America head - with exhaust port injection points. I don't believe the stories about extra thickness etc - it's exactly a 940 head as far as I can see - I have one 'in stock'....

[gatsby989]

So can the 12G1316 head be fitted to a 948 just like a 12G940? Since the 12G940 head seems basically unobtainable here.

What does one do about the exhaust port injection points?

[bmcecosse]

Yes -just treat it exactly the same as the 940. On mine - the ports have plugs fitted. If yours are open - just plug them......