Edelbrock Streetmaster 318 vs regular performer

Hi guys! I was wondering if any of you have replaced an old streetmaster 318 intake with a perfomer manifold? If so, was there any improvement in performance? I am very happy with this old streetmaster relic but I am curious if there is any more power to be had out of this little 318. Even with 2.94 gears this car puts you in your seat first and second gear! It is a stock 76' motor with 8k original miles. The only mods are a comp xe268 cam, 340 springs and 1-5/8" headers. This is actually in my factory 4 speed 76' Aspen coupe with 8,091 original miles.