I changed the timing on my car from 20 advanced (Bought it that way) to 16 since that was the lowest it went without dying. Since then a humming noise is made from start to finish and sounds like the fuel pump area. I was racing by friends cobra and then it starts studdering but not doesnt die. What can be the problem

 

That is pretty severe spark advance numbers. You may want to review your timing procedure.

 

...and get a new pump. they will hum loud and cut out before totally dying and leave you stranded.

 

The car doesnt want to drive at normal advancement

 

either your distributor is a tooth off or 180 out, or you forgot to unplug the wire on the pass side up by the blower motor when checking your timing

the car really should not be that far advanced if its in stock form,i see you have a GM crate thats a 355, factory spec on any thirdgen i have seen is 0 degrees BTDC,but even with the 355 and exhaust you should not be to 16 degrees, make sure you unplug that Brown(i believe) wire before checking your timing