Much on that here:
Is it true that the T-34 was built in the United States during ...
They did borrow their suspension system from the American inventor Christie. It gave them better cross-country speed and the ability to travel better on soggy ground and snow. The Soviets also added sloped armour. See: Christie suspension - Wikipedia The T-34 was better than most German tanks and much better than US tanks. The Soviets manufactured the T-34 is massive numbers. They made over 84,000 of them and simply overwhelmed the Germans. See: T-34 - Wikipedia...It was not until the introduction of Pershings with their thick armor and 90mm M3 gun that the T-34-85s became fun-food for the U.S. - Alan Blair, former Software Architect for a Number of Military System at General Dynamics
HOWEVER, it was thanks to this American gentleman [Albert Kahn] that the Soviet war making industry could produce so many T-34s:...the T-34 was invented and manufactured deep inside the Soviet Motherland but the factories had been built by American architects and engineers, and much of the machinery had been imported from America in the 1930s.- Duc Quyen, World War II fanatic
I am one of the few who knows what you are talking about. Yes, we could have had the T 34 but we opted for the M4 Sherman. There were probably lot of politics involved in defense acquisition and there always will be. BTW, Christie also tried to sell it to the British and French among others and they all turned it down.