my buddy has some 241 ls1 heads he's been tryin to sell me..are these heads worth getting milled and put on my 5.3? whats the combustion chamber on these heads? opinions needed..

 

66.67cc.....you're better off with the stock 5.3 heads

 

how much can you mill these with the intake still fitting properly? flow much better?

 

I've seen .045 taken off and the intake still fit right....

With the smaller bore of the 5.3 and the larger valves in the 241 heads you're going to shroud the valves quite a bit....whether or not the extra flow from tha larger valves will compensate for the shrouding that will occur is anybody guess.

I went with the 241 heads because of chamber size and material (stock 6.0 head are ~71cc and I had cast iron heads) but with a 4.00" bore I didn't have to worry about valve shrouding