I was told that these were patriot heads. When I spoke to Gunnar at Patriot He did not think they were made by them. Any ideas would help. So far all I know is that they are 862 casting 5.3 heads.
I did not get a picture of it but there is a 75 stamped into the front and rear of the heads.

 

5.3L, could have searched and found out too.

 

Maybe wrong, but the retainers look like a PRC retainer.

 

They definitely have a PRC spring kit on them.Where did you buy them?

 

That's our spring kit and with the 75 stamped ont the end, odds are it's ours. If it is, it would be a set from last June I believe.

Brian

 

I agree, looks like PRC chamber design too so odds are.

 

Well that is definately a 2.04 intake valve on stock seat (another indication of TSP)