so after i finished my head swap my engine started making an odd noise. It is almost like a whisper... pshhh pshhh pshhh. I think it may be an exhaust least... could use some opinions

 

sounds like a donut gasket leak from the header.....does it get louder the harder you accelerate? put your finger down by the connection to the collecter and if you feel hot air hitting your finger thats the problem

 

I nominate exhaust leak at the manifold. Replace the gasket. Did you remember to tighten thebolts after driving it a little?

 

the manifold is fine, I have tested the vacum

 

durrrr....nvm, Im thinkin wrong manifold here.

 

If you replace header gaskets I'd recomend Fel Pro 1415. It's a steel core with composite facing on both sides, holds torque well so your headers don't constantly rattle capscrews loose, and it can still move around and let the header/heads expand and contract and still hold a seal.