Land Rover Repair: 3.9 efi head gaskets (1991 Range Rover), blown head gasket, hydraulic tappets

Question
I have a blown head gasket and am currently in the process of replacing it. The original is the metal gasket, now I have heard that there is a composite replacement for it. This reduces compression a bit, but I'm not too worried about that, but I have the following questions for if I choose to replace the gasket with the composite type:

1. Do the pushrods need to be replaced for longer ones, because the composite gasket is thicker, the distance from the camshaft to the rockers is larger? Or does the self adjusting nature of the hydraulic tappets take care of this?

2. Because of the reduced compression is the engine characteristic changed in such a way that the ECU needs to undergo re-chipping?

Thank you.

Answer
Usually we end up resurfacing the cylinder heads to make them flat again.  The few thousandths you take off makes up for most of what you lose in thicker gasket.  I suggest you do that.

You do not need longer pushrods.

You do not need to re chip the motor