gen 4 heads

[fozwanger]

I've been told that gen 4 heads fit onto a gen 3 motor. Can anyone confirm this and do they know what else is invloved?
Can I use the gen 3 inlet and push rods etc or is it a total mare.
I've also been told that the extra 100 hp gained by a gen 4 is through head work, and that the vvt generates a better torque curve at revs.
Folks, enlighten me.
(I have spoken to Chuck Tator, and I feel bad because I keep emailing him)

[fozwanger]

Eodd at Arrow racing engines is the guy to speak to, really helpful

[Viper]

Arrow used to do the engine warranty work for Dodge (not sure if they still do) but they have a great name and engines come back better than new