An insulator is a must for these or really any carb for sure. I’m not seeing what benefit blocking the compensator brings to the table. It’s already blocked unless enough heat is built up to open it. I suppose it could create turbulence and decrease airflow, but who would’ve done a test to see if it was even measurable? I haven’t taken an avs apart in years or looked down in one that had that part in that time. I don’t think it overhangs the bore so still not seeing a way it would hurt flow. My car has the correct number avs and has factory ac. I’ll have to look down it and see if it has one.