Your only gaining DCR to loose out to inefficiency and lower power output for no reason. You will have a better combo with a lower DCR and the open chamber head. The myth that people can't seem to wrap their head around is that with the 6 cylinder, unlike other engines, the closed chamber head does give a boost in compression yes, but it also results in a HP lose across the entire RPM spectrum compared to same components using the open chamber head.....so what are you gaining?
Yes, you are correct in your understanding of the how and why the 194 head shrouds the engine. So knowing that this is going to occur and you will lose HP and engine efficiency, why do you think still this is a good choice? There is no gain to be had that will be of any advantage at all except that you will now have to run premium gas with no increase in power.
Don't get me wrong, its your money and your build. Just don't be fooled into thinking you are getting a gain when you really aren't.
I didn't say it was a good choice. I was commenting on having to mill down the open chamber head to 64cc to get the advantage of using high octane fuel with the engine parts combo. I'm not even sure if an open head can be milled that far. But yeah, if you have a choice of running premium with a 194 head, or running regular with a milled down down open chamber head, both making the same power with the same cam then you might just want to go with regular gas. But you might even be making less power with the 194 head over the entire rpm range, so using regular gas seems like a better option.
The DCR numbers really show the L6 and open chamber head to be optimized for street builds with cams under 260 advertised duration, but it gets harder and harder to hit that DCR of 8.5:1 without hitting the stock heads limit on milling. I've only got Comp Cams and Crower's cam cards to go off of. Maybe there are some other manufacturers with ABDC that gets you closer with more street/strip profiles.
