Outside of nuclear weapons, what would you say the three most important technology transfers made by the US or UK to the Soviet Union during WW 2, via Lend-Lease, were? I'll put my three in a bit later once some others have answered.
Interesting question. I'm not sure what you mean by technology transfers, but I would give my vote for transportation goods, trucks especially. Given Soviet distances, trucks, jeeps, etc. were important. This includes such technology for building concomitant industries such as tires. Separately, I would mention rail facilities. We shipped large numbers of locomotives and rail cars to aid in the distribution of goods. I'll have to think further for a third transfer. Let me know if this is not what you were thinking of.
The Basics. Food, ammunition that sort of things. They had probably already stolen everything else. Not that they could provide themselves.
Okay, the P39 ! They Loved it if I remember correctly. copied and plastered: A total of 4,719 P-39s were sent to the Soviet Union, accounting for more than one-third of all U.S. and UK-supplied fighter aircraft in the VVS, and nearly half of all P-39 production. Soviet Airacobra losses totalled 1,030 aircraft (49 in 1942, 305 in 1943, 486 in 1944 and 190 in 1945).
I'd say, in the long run, the 3 that really had a lasting impact were: The B-29 where Russia got several that were interned after raids on Japan where the crew chose to land in Russia to avoid capture. The SCR 584, of which they got several sets late in the war. Without these, the Soviet Union would have been 10 years behind the West in radar technology in 1946. Military grade trucks.