tappets

is it difficult to adjust the tappets in a gu petrol

No more difficult than any other car.
Check this thread for more info. TB45 is the same as TB42.

http://www.nissanpatrol.com.au/forum...usting+tappets

Tony

paul1351,
Make sure you make the adjustments with the motor hot or at least warm. If you do it cold, you will probably end up with a noisy tappet or two i.e. too much clearance - and/or worse, a tappet or two with too little clearance (worse because you can't hear them), which might be a cause of a burnt valve. Take your time and when you think you have finished, turn the engine again and re-check all clearances - you might be surprised.