Markings on V8D heads

[ITVRI]

I've recently purchased a pair of second hand V8 Development (I think) stage 3 heads for my Chimaera 400. They have numbers 317 stamped into them. Does anyone know what this refers to? Yes I could call and ask V8D but thought I would ask on here first.
Picture here.
https://drive.google.com/open?id=0B9ViSEdlVcDmMHB4...

Edited by ITVRI on Friday 5th August 22:11

[phazed]

Whereabouts on the heads are the markings?

[ITVRI]

At the end of the head, on the inside front

https://drive.google.com/open?id=0B9ViSEdlVcDmUjJk...

[phazed]

Hmm, got nothing on my stage 4's.

[QBee]

Measure the valve sizes and post the results on here.

The things that matter are:

1. Valve sizes
2. Porting

[Searider]

I would think that 34.5cc is the volume of the combustion chambers

[ITVRI]

Valves are difficult to measure exactly without vernier callipers but looks like inlet 41-42mm and exhaust 36-37mm.
Exhaust and inlet have been smoothed out and has double valve springs and bullet guides.

Inlet
https://drive.google.com/open?id=0B9ViSEdlVcDmUm5I...

Exhaust
https://drive.google.com/open?id=0B9ViSEdlVcDmZVUx...

Chamber
https://drive.google.com/open?id=0B9ViSEdlVcDmMzRk...

It's the number 317 and what that refers to that I'm wanting to find out more about. I was thinking 3 in 317 could refer to stage 3 or it could just be the production serial number

[Boosted LS1]

Third best pair ever made in the past 17 years :-)

[Dungman]

I have v8d stage 3's. They also have a 3 digit number but start with a 5.

[ITVRI]

Ok thanks Dungman sounds like it's likely a serial number.

Edited by ITVRI on Saturday 6th August 17:23