HoldenGemini.net Forums :

Where can I get some decent rear shocks for my '86 model ? New or second hand- I don't care as long as they work. I replaced mine 12 or 18 mths ago months ago with some new rubbish, and now after that short time they are stuffed ! Does anyone know if shocks from some other model will fit ?
Cheers,
Nitram

I recommend KYB. Usually quite cheap yet robust.
I'll bet the Jap Gems had them - the Belletts did.
And I bought a pair for my Wasp 11 years/180,000km ago and they are still fine.

(The only other brand I have generally bought are KONI/IKON.)