Determining RUF motor
 

How can i authenticate if its a real 1979 3.2 RUF engine? What would it be worth rebuilt?

I have been trying to figure that one out as well.

One way to semi-verify a 3.4 liter turbo RUF engine is to look for fully finned cylinder barrels. The 3.4 liter cylinder is fully finned top to bottom where as the 3.3 liter stock Porsche barrel is only half finned. Perhaps the 3.2 liter you speak of is similar.

Call Ruf with car's Vin number.

The motor is not in a car and owner claims car was wrecked and he bought engine which is a 1979 3.2

Probably just some Ruf parts installed during a rebuild.