I was wondering if anybody knows if you can put the 3.0 v-6 in a car with the i-4 without changing the trans?

 

never seen it done before. Don't think its possible. Better off going the route of complete motor and trans swap.

 

Would be much cheaper to buy a whole new car (or used for that matter).

You would need a J-series transmission, of which any will work, for example the J32 Acura CL Type-S.

The V-6 is a J30aX motor, so you need the mated transmission.