IN MUMBAl OR NAVl MUMBAI

Modifications & after upgrades r by & large dependent on the tastes & requirements of the owner. You should be very clear about what u want - like what kind of ''upgrades'' to the engine do u want?

You want only the engine to be modified?

You want to modify the engine, or achieve something particular (like more power? or u want more torque?

Be have very clear ideas abouth such issues; & then discuss with the guy - whoever he is.

And any reason to stick with eht sierra, which is no longer in production, rather than get a brand new car?