I'm just know starting to move past researching bolt-on mods, they're sitting waiting to go on, and am now looking into heads/cam and have basic questions. Thanks in advance for your help.
Ok, obviously if you use 5.7 heads and don't mil them any, you'l have stock compression. My question is, will putting 5.3 or 6 heads on the motor change the compression, and if so which way will it move the compression/how much? I thought I read that people use 5.3 to raise compression, and 6 to lower compression, am I remembering correctly?
Then,why is it taht tehy change the compression? Does a 5.3 raise it because of a shorter deck height, or is ti because teh comubustion chamber is different? Basically, is a 5.3 the same thing as a 5.7 milled slightly, or not? My question really comes from whether a cam would work with the 5.3. If a cam works with the stock heads, would it then work with the 5.3? It depends on the cam obviously, I'm just trying to figure out if the head is lower so then it's more likely to cause clearance issues.
So if having a 5.3 raises the compression, what is the benefit of using a 5.3 head vs. milling a 5.7 head to raise the compression that way?

 

This answers you head CC question. As for a certain cam clearing or not, you need to tell us what cam you plan on running first.

https://ls1tech.com/forums/advanced-engineering-tech/111207-ls1-head-combustion-chamber-cc-volume-vs-cr.html

 

It was more of a question if a 5.3 head is lower than a 5.7 head. If it is, then it will obviously increase the chances of clearance issues.