i hace 4g wire running to my block. im running a 800.1 bassworx amp and a 75.4 bassworxs amp off the block right now. i was planning to add another amp to my system. a 75.2 would the 4g running to my block be enough for all this power? or should i upgrade that 4g?

 

You should be fine for the most part 4gauge under 20ft should be able to handle 100-140amps which equates to about 1000-1400Wrms you should be fine. As you do not draw full power all the time. BTW when I tell you this the 4gauge I am refering to is good quality wiring not chinese 6gauge copper 4gauge size covering.