Check the bolt pattern on the two engine blocks. If the bell housing and flexplate/flywheel fits, then you can use the same transmission. If they don't fit, use the transmission from the 5.0
no unless your transmission doesnt have the tourqe rating enough for the bigger engine but that still depends on how you drive if you shift to fast assuming its a manuel to catch gears it might fail and tear a gear out or a syncro if it will bolt up i wouldnt replace it unless your just wanting to "raise some hell" if its an automatic i most definatly would give it a try worst thing could happen is it break due to horsepower and tourqe overload then you could switch to something a little more heavy duty sae mechanic 30 yrs