Hi does anyone know where i can get a not to expensive nearside manifold for a 1995 3.9 V8 Discovery. I have looked everywhere.

I have a problem with my 1994 3.9V8, The problem started about a month ago with the rev counter acting funny, when i hit 2000revs it shoots upto between 4-5000 revs depending on the speed. The engine isnt racing. When i use anything electrical it then affects the rev counter. When the vehicle is...