Air gap manifolds in cold weather

Thanks for the replies.

I going with magnum heads, it doesn't look like there are any manifolds with heat crossover.

The Mopar M1 dual plane looks like it has something for water heat crossover but I can't tell for sure.
Does anyone know?

edit:
I've answered my own question, summit have a 360deg. view of the manifold and you can see that it uses coolant for the manifold heating.
Thanks.