The one in my half ton is actually an SRT8 not the BGE and the heads were milled down to eagle size 65CC (I think I ended up around 11.5 compression) and a little touch of porting.

I am trying to decide exactly what to do with my 6.4 I am building for my 2011 ram 2500 I just bought (locked up 5.7). I think I want to run either the BGE MDS cam or stock 5.7 MDS cam this time to trade a little top end witch there is no shortage of for a little more low end TQ. I have a complete BGE engine and a spare set of SRT pistons, injectors and cam to convert it so I just need to finger out what compression and cam combo I want to run (can't afford a custom or any aftermarket cam really), how much cylinder pressure do I dare run (SRT8 in current 1500 ram runs around 210-220 PSI? I am currently thinking BGE pistons zero decked (about .020 down right now) mill heads .020 and run .030 head gaskets and I should be just under or at 11 to 1 then run the 5.7 cam, SRT8 injectors and a 90 MM throttle body, that should work real good with the 5.7 stock tune but add a butt load of TQ down low. Im trying to think of it more as a bored and stroked 5.7 instead of an SRT or BGE engine. There is even a small part of me in the back of my head saying run the eagle heads for easy compression and higher velocity but the BGEs I have do use a better metal to conduct away and spread out the heat better, sodium filled ex valves and an even better chamber shape... I think the SRT pistons and smaller cam would just be too much cylinder pressure but maybe it could take it??? Honestly I always get scared when building a really high compression motor because it is a pain to go back in and lower it if needed.

I sure wish e-85 was readily available here I would zero deck it with the SRT pistons, mill the eagle heads .030 and run the 5.7 cam and really make some cylinder pressure.

I am a firm believer that most any factory engineered engine can easily take another half or even full point of compression (some even more!) but they are compromised to minimize NOX and warranty claims from people using the wrong grade fuel.