Ok, so you are saying peak flow number comparisons aren't going to be the best way to compare cylinder heads. Fair enough.
Can you explain that a little more? Better in what way? Packaging? Smaller valve cover?
I'm not trying to say you can't get a LA/Magnum to cold start and idle. I'm just saying that a carb'ed 408 isn't going to do either as well as a 5.7 or 6.4. And the more ragged edge the 408 is built, the less likely it will do it without constant tweaking.
I guess I am looking at it from an "other than theoretical" position. I love the ide a of a W2 headed smallblock. But the idea of finding all the parts and making them work together makes me say a 5.7 is the better way. Would a W2 outrun a 5.7 if they were equally built? Maybe, don't really care. Could you build a W2 headed motor that has equal drivability as a small cammed 5.7 and still outrun it? I have doubts.
I would love to see that done though. Don't get me wrong. And it might already have been done. I know
@racerjoe has a trick SBM with EFI and CNP. Maybe he would be a good one to give input on building a nice driving SBM that get's good fuel economy and makes great power. Another one is
@goldduster318. He has a fully EFI'ed SBM and even a T56.
I guess they way I see it, I can buy a BP 465 hp crate motor for $9K and get probably 16 mpg. Or I can do a complete 5.7 swap, including a 6.4 cam and intake, and make about the same power but with 25+ mpg and better drivability. Maybe as you assert the G3 Hemi head isn't as good as the Edelbrocks on the BP motor, but the results kind of say otherwise.
