I did try NGK's and she didn't like them one bit!

Don't get me wrong she runs great apart from a squealing belt.. Jeez, new leads every 10K thats crazy! i cant see me needing another set for a very long time as the 1st set lasted years!

Its not a backfire i don't think, it always comes from the cat and makes a tinny pop instead of a bang, sounds like i ran over a soda bottle, it doesn't cause me too much hassle so unless it gets worse then i will take it to the LPG specialists.

Great to hear about that truck