Picked up a 318 streetmaster for the 273, good or bad?

In the mid 80's a buddy of mine had a stock 71 Cuda with a 318 and he put a streetmaster on it along with a 600 Holley and that little teen really woke up. He never ran it at the track but he did run it on our local back road 1/4 mile before and after and with the streetmaster it ran 7-8 mph faster.