OK ! I live in Russia (sorry for my english!)!

In my country there are no such high-powered engines and therefore I wanted to acquire it in America through the Internet!
But I do not know what engine to select! To me so it is must gearbox and rear axle, Because in my machine that parts very not reliable and weak!

Its a old Russian Car 79` Moskvich 2140.
Unfortunately little which remained from this machine, but I had time to purchase original spare parts, only exterior view, and I want to change entire filling for the American power


So, I will be grateful for the council!