Anybody put these on a 5.3? If so, how much did you have to mill to keep compression up? It would appear from AFR's site that it would require ~.030? Just seems like a lot of milling, and their site says that milling will impact the flow #'s. If milling affects them too much, I might be better off with some milled, stock LS6 heads. Will I have any P-V clearance issues after milling with a 210/218 .581/.581 (1.8 rockers)? How do determine my pushrod length?

 

Nothing against the guys here, but the sheer volume of experienced people over at LS1Tech.com will ensure you get a good, accurate response to this question.

Have you posted this over there in the LS1-LS6 Internal Engine section?

 

Well For One With 581 Lift And 1.8 Rockers You Would Be Over 600 Lift.
It Would Be 615.17.
That Would Give You A Problem.i Am Running Heads Milled 30th.it All Depends On What Cc Is The Combustion Chamber.

 

Should have been more clear. The .581 lift is with the 1.8 rockers. AFR says milling them .030-.035 is not a problem, and that they routinely take the heads down to approximately 62cc's. However, the guy at AFR was not familiar with the 5.3 motor at all, and he had no idea whether the cam would have P-V issues or pushrod length. He also indicated that a 210/218 is too big of a split for their heads and that it would not 'maximize' low end torqure or top end power. He recommended something more like 214/218. He said this was due to their I/E airflow ratio being so much better than stock style heads. He also indicated that the .580 lift area is a 'sweet spot' for their heads.

I did make a post on LS1Tech to see what kind of responses I get: https://ls1tech.com/forums/showthread.php?t=379127