Early 911 Heads Question

[Henry Carraro]

I recently bought a collection of Porsche parts from an autocrosser who had amassed quite a collection over the last 20 years. Included in this collection were a number of 911 items and or 914-6 items that I am having trouble identifying.

For this post, I would like to ask for help understanding the nomenclature on 911 heads. I guess my question is this, on the seven heads I have, it looks like Porsche part number on these heads is the same, i.e., 911.104.342.2R.

Aside from normal casting numbers, I am assuming the other important number is the date code. Am I correct in my understanding that 1/75 indicates a January 1975 manufacturing date? One of these heads has a 76 only marking.

Here's the dumb question, assuming my understanding of the date code is correct, how can I find what motor these heads fit? I have ordered a 911 Technical Specifications Book but it hasn't arrived.

Thank you in advance for your help. It is greatly appreciated.

[911quest]

some one over at the earlyS registry has a chart might give it a try over there

[MBruns]

It started life as a 2.7 head 1976-1977
Mike Bruns JBRacing.com

[tom1394racing]

Go to the CarQuip web page and check out their 911 cylinder head table. The date stamp combined with the valve and port size will allow you to identify any 911 cylinder head.

[jluetjen]

That's right. The number that you see on the head is the casting number, which is basically the part number of the head prior to any machining operations. It was not uncommon for Porsche to use the same casting for multiple versions of it's engines.