I have a 2003 Silverado SS with the LQ9 and think its about time I upgrade the engine. From what I've read I should be happy with 823 L92 heads, an LS3 intake and a new cam (along with tune and headers). I am looking at a used set of heads that are complete. What should I check before purchasing used heads or am I better off just buying new heads? I'm thinking I can get these for around $600 Canadian and he also has an LS3 intake that he would give me a deal on as well. He doesn't know mileage, hours, age of vehicle it came off or any details like that (sketchy to me...)



Any help would be appreciated.

 

Look for cracks ,look closely in combustion cambers for anything bad looking. LS3 intakes came off of cars and l92 intakes came off of trucks Id have it taken to a machine shop to be looked at before install also. The heads new are about 1000 USD so keep that in mind.

 

You could also find a level and put that on the head to see if it is warped also.

 

going to run a stall? those heads are really doggy at low RPM and part throttle. i've been through this exact dilema with my old formula, and wish i had actually listened to everyone and stuck with cathedrals. i'm even thinking about ditching the 823's on my Denali and going with cathedrals. they really suck below 3k rpm in a truck.