hi i would like to know which is the best ecm for my eng. i already have a custom chip that is to my eng. i would like to keep my chip. it is in a camaro /trans am style ecm. what are the pro of going to the better ecm over one that not so good ?

here is what i am work on , an what i have got. working on puting a 350 tpi that is going in to a 79 elcamino with a factory 4 speed . the 350 tpi has accel intake, diffrent cam (not sure what it is ?) ,high than stock compression (has 64cc heads) not sure of cr. i got a good deal on the eng so i am not sure whats all in it.
has a few more mods too but i think those are the most impartant things u may need to know , to help me right now.

any help would be great thanks chad