Marcos Maniacs

Hello,

I am new to this group and own a 1996 3.9L V8 Mantara, live in Hampshire,
UK and many years ago owned a 1972 Volvo 3L. I have a few questions which
hopefully someone will be able to answer for me:

What is the best engine oil to use?
What is the best gearbox oil to use?
Where do the front track control arm inner bushes come from?

I also suffer from the engine failing to consistently returning to the
correct tickover, but it looks like this is known about and does not appear
to have a simple solution.

TIA