I have installed my cam and I am wondering what would be the consequence of an exhaust system that doesn't flow enough. My Flowmaster is flowing less than my stock muffler that is for sure ( 2 x 2.25" in/out) and probably building more pressure into the heads. I am no mechanics but could it affect my oil consuption and/or antifreeze consumption/deviation?

I have noticed a slight oil consuption maybe 1 quart in 3000 miles. I put all new gaskets and followed the LS1 how to guide meticulously.

Oh yeah, I'm pretty sure I have one valve not closing evenly. It dropped in the cylinder while doing the swap. I took it up by removing the manifold. It's the front valve from cylinder 8.

 

1 quart is pretty normal man, nothing to really worry about.

 

1 quart is normal for 3000 miles. I have the stock exhuast on my truck and I honestly dont think it hurts me that much. I'm curious to see, but anyway....Your cam is a bit bigger than mine though, so i could see that your top end might be hurt.

 

Better flowing exhaust will only help you. It wont Hurt you!