To tell the difference between an A12 GX head and A14/A15 oval port:

* A12 GX has no casting numbers (at least the ones we've seen)
* A12 GX has much larger ports than A14/A15 heads: 30x34.5 vs 28x34

wiki - Cylinder Heads

IF, ... the double valve spring head is an unmolested original, & IF, ... it has the larger valve sizes, ... then you probably have a head from an A14 GX.
This would have been removed from an import engine.

had a looks at the casting numbers on the heads and they read H89 - 604 and H89-617 so they must be a15 type heads but 1 of them has double valve springs which is what confused me .......
thanks guys for your help

my bad cheater :)

A10, 1200's & a12's, including GX, have smaller valves [29 & 35mm]
A14 & A15 engines have larger valves [30 & 37mm]

The exhaust ports for all A series engines are square. [crzy_1200_ute was just geting a little crazy there for a moment]
Oval shaped inlet ports were used on 1200GX, A12GX, plus Aussie versions of the A14 & A15.
Round port heads were seen on A10, plus regular model 1200, & A12 & some versions of the A14 in some overseas markets.

A10 & 1200's have additional drillings for rocker oiling.

wat crazy 1200 ute was meant to say is that a12's have round (circle) ports, a15 has oval and some a14s have circle and some oval. all exhaust ports are square and are the same size

thanks guys

so what are heads with round ports ?

Check the Tech Section, there is a listing of all the casting numbers and other differences.

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*edit, beat me to it!*

easyist why would be go to the tech section on the site.. :)

and now for the answer.. A12 has square ports A15 has oval ports

I was wanting to know if anyone can tell me the easiest way to tell the difference between an A12 AND A15 head (i asked the so call experts and they told me they are the same)
15 oval port heads look the same as gx head to me but cant work it out


also how to tell if a gx head is the real deal