kill4thril

So I build a 350 for the car a while back and put my stock 305 tbi system on it with the ebl ecm and the car ran good for a few months then started breaking up anytime I tryed to take off from a stop or really got in to it and at a steady pace like on the high way it would feel as if the car just shut off so I didn't know to much about it back then so I put a carb on the car and called it a day but a few months ago I got my hands on some tpi parts and just recently put them on the car and had the ebl sent out to get the port mod and now the car does the same thing and I am out of ideas on what it is everything on the car is new all sensors but I am not 100% if the knock sensor was for a 305 or 350.
When I pull up the table for spark advance its just a bunch of spikes all over the graph from 0* to 40*
If anyone has an idea on what it might be that would be great
Thanks for the help
Jesse