GQ Patrols fitted with the TB42s (carby model) run a points type Distributor which have an overly large air gap between the rotor button itself & the distributor cap.
This has been well none & documented to course problems. Some of the side effects of this large air gap is missing at idle & missing under load. This problem is amplified when running LPG but not exclusive.
To combat this problem a company in Melbourne developed an extended rotor button for the TB42s points type Distributor which has been met with great success.
Here is some pictures of the re-developed rotor button & you can find contact details at the bottom of this post.
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Extended rotor Button from Performance Ignition Services. 03 98723644
Price is $80, inc GST.
They do changeovers, at $35 plus $45 deposit.
Overnight freight is from $11 if required.
http://www.performanceignition.com.au/
Cheers
Paul