Motor dies
 

OK here is what I got, 305 HO out of a 1983 truck. Id got a holley 600CFM on it and it runs very well. Now when the motor heats up, the motor seems to not be getting enough air and will die on you, take the breather off and it will run fine except the occasional back-fire. Now my question is, what can I do to fix it? The breather is a 14in, round breather, nothing special about it, you can get it at autozone for like $30.