Is it absolutely nessecary to tune a car after adding just a stall convertor?

Thinking of going to a 3800 but would like to hold off until I do a H/C upgrade.

 

yes you would need to get your car tuned. i believe codes P0751, P0757. those codes popped up after getting my vigilante 3200 stall put in.. something about the solenoid being stuck. made my car horrible to drive. after getting those codes deleted my car is perfect.

 

Alright,thanks for the replies. I guess I'll hold off on installing the convertor until I do the cam and heads and tune it once.