I have my 01 ls1 forsale 5.3 heads on it,Has the double roller chain comp r lifters, f1 cam .591 /.569 , 112lsa Has about 20,000 miles on the engine. apart . Two of the head bolt holes cracked where someone didnt take the water out the holeDuring a head swap. Doesnt effect anything performance wise. Block is fine doesnt leak or have any problems, except piston slap when cold. A little noisey since we did the cam and lifters. I would like $900 obo for it. Will include a ls1 intake with it. No valve covers though since mine are powder coated.