01 firebird 5.7L. when im driving i hear a gurgling sound. it also sounds like marbles?

Question

the sound usually occurs when im going about 50mph and then i slightly step on the gas maybe half way and i hear the sound. im just trying to figure out what it is.

Answer 1

The sound you are hearing I beleave is knowen as a spark knock
It could be from an number of reasions
#1 wrong gas( regular instede of mid grade or premium)
#2 Wrong timing( have it checked)
#3 Bad sparkplugs ( breaking down under load)
#4 An anti knock sensor going bad
#5 Bad wires.

All these thing will cause what I beleave you are hearing
Hope this helps

Answer 2

the muffler bearing needs to be aligned to its optimum speeder gear train.