anyone know? which is better?

 

Out of the box I believe the G2s have a little more flow. Physically the intake valve angle on the G2 is canted ~16° and the chamber "twisted" around bringing the intake a little more over the cylinder.

Between those two heads I wouldn't even hesitate, their 23° head is the only way.

 

anyone else? any flow numbers or anything?

 

I would go the other route with the G2s (if i wasn't an AFR owner).
All the literature I've seen and guys I've talked to say the G1/G2s substantially outperform the 23*. There have been problems with valve guides and stuff with the early models the G1s, but supposedly the G2s have solved that.
I have seen more than enough twisted wedge cars in the mid to low 12s at 110+ and not one 23* car in the 12s at all or with a decent trap speed.
this is just my observation, and anyone feel free to prove me wrong.
I think part of it is that not many people run the 23* yet, and the TW heads are already established.

 

Well, I went with the 23*heads. I need to save all the money i can, and I've heard nothing but good about them, so I'll see if it's the truth when I finally get my engine built and installed.

 

arent the g2 heads canted? in my opinon thats a good idea to unshroud the valves and get more air into the cylinder. but i dont know anything about the 23 heads.

 

I should've been in the 12's last year, but I couldn't do a good burnout or hook up off the line due to the crappy Torsen diff. I will be in the 12's this spring, hopefully this Friday if I get my new diff installed by then. I was hitting 105 mph with a restrictive muffler and poor tuning (spark/fuel) and half-ported SLP runners (still haven't finished them yet), so I'll be laying down some good numbers this year. In CHP's cylinder head testing, the 23* heads flowed almost as good as the G2's and were just about even with the AFR's, although airflow isn't everything when it comes to making power.