What is the stock compression ratio of a 6.0 with 317s ?
With stock 243's?
What would be the difference in performance if a stock 317 head was milled to achieve the CR of the 243 head?
also, what is the chamber size of the two heads? thanks

 

with the 74 cc chamber 317's around 9.4:1
with 64cc chamber 243's around 10.5-10.6:1 depending on your true combustion chamber volume and your piston to deck height

 

I thought the 317s came on the LQ9 putting it at 10:1.

 

both lQ4 and lQ9 come with 317"s the only thing differnet is the pistons that's what makes the c.r.

LQ4 dish pistions 9:6
LQ9 flat top pistions 10:1

if you take 243"s which are 64cc on a LQ9 you should be at 11:1 like the ls2

 

so does anyone know if I could swap the pistons from a 4.8(flat top) and put them into a 5.3(dished). what would this raise my cr too? I have a set of poted 243s, and I really dont want to mill them so they are unusable to anything but a 5.3

dont mean to steal the thread, but so far all I've been told is to chop them down and if I dont punch my 5.3 into a 5.7 now i'll be doing it in the future, and I don't want to pay another grand on a good set of heads.