For your application, the turbo 400 will work the best for you. But you have a converter issue with that 8" BTE. Not the right converter for your application at all. I would call BTE or contact Oldani in the trans section here. He is also a BTE dealer. Either one will help you with the correct converter.
Looking at your motor specs you posted. That cam is to big for what your doing. The heads are OK, but you will not see any benefit from that big of cam. The heads do not flow enough for that cam! Nor were they designed for that big of lift. They are very porus, and you may pull the stud right out of the boss. You have alot of spring pressure with that big of lift. In this case BIGGER is NOT BETTER. Contact Ed @ edvancedengines in the motor section, or cboggs.
Dave