Hi all, New to this so bare with me please,

Just fired up a new LQ4 6.0 with a Trick Flow 515 upper engine kit and i'm hearing a noise that sounds a lot like a diesel. (It's the best way i can explain it)
I've checked push rod length and the first set I had was to long. (7.500)
ended up using 7.450 long push rods, the noise is still there!
I just pulled the motor out and inspected every inch for something rubbing or scaring. still nothing evident
Can anyone give me any ideas what to look for:

 

Well I think I found it !!!
Removed the heads and found that the head gaskets are hitting the top of the pistons😢
The upper trick flow kit head gaskets are for a 5.3 not a 6.0 LQ4.

 

get new gaskets from Texas Speed or SDPC .don't reuse the heads bolts unless they are ARP bolts.