Can anyone tell me what the height of aN LQ9 head is? I'm trying to determine how much I can mill the heads to acheive a 10.5:1 compression ratio. I also need to know if I mill the head to acheive this compression ratio, if it will work with a 224/563-114 cam with out piston to valve problems? Any help would be appreciated, thanks!

 

I got my hands on a micrometer, so I was able to answer my own question! So for all of you guys out there who might have the same question, the answer is.............the LQ9 head height is the same as for the LS1 (4.750"). Measurement was take at the rear of the head, from the valve cover rail to the bottom of the head.

 

confirmed, just checked a bunch of 317 castings and come up with same #. for every .006 removed on straight milling, equals about 1cc decrease in volume. you need to check P/V because every case can be a little different.