I am looking to do some upgrades on my motor and have a way to get a brand new set of c5 ls1 heads with the cast # of 853.Will these work on my 2001 4.8l rcsb and if so what cam should i run,as i just ordered a set of Lts for that project.I know i will need a tune as well.but if these will work itl be a great start.

 

They will work fine. Only thing is they have perimeter bolt valve covers so if you don't get the appropriate covers with them your current center bolt covers will not work, thus your coils will not mount up. You will also lose some compression, they have a larger chamber than your current heads.
A minor issue if you get the heads for a good price.

 

I got the heads for free from my friend,can i expect any hp gain over my stock heads?I wonder what cam i should run also am mabey see if a bbk intake manifold will bolt up as well.HMMM

 

the heads will work shave 50 ths off and do a 3 r 5 angle valvve job,for as cam i would run 1 out of the 01 ls6 cam with 918,com 212/218 high lift,r a custom grind 216/220 564/566 on a 116+4.for as the intake i would get e-fans,and pulley,cai,before the intake