Well, as you said, the turrets differ but the hulls are essentially the same. You could pull off the conversion or you could not be a cheap @ss and buy the appropriate kit.
Seriously, you will probably build a T-34/85 sometime in the future right? So why not get the correct PE kit and not have any regrets?

Andrew

Aber PE sets are nice, but to say whether or not it is worth it depends on the T-34/76 model you are putting the PE set on. For the price of the Tamiya kit, you do not get a very accurate T-34. Believe it or not, the various Zvezda T-34/76 kits are superior and about half as much. Italeri also boxes the Zvezda kits so find whichever is cheaper. DML makes even better T-34s as does Maquette, but I do not know if they do the T-34/76.

So, IMHO, Tamiya T-34 (any of them) not really worth it. Zvezda, DML, Maquette, sure. It will enhance a nice model and make it better.

BTW, I have an e-mail clearance special that George Parada sent me. He has Part (PE company from Poland) sets for the Tamiya T-34/76 for $12.00 and T-34/76 (1942) for $10.00. Part PE is very nice. Shoot me a PM if you want me to forward that e-mail message to you. He sometimes advertises in our buying and selling forum as well.