Insurance for high end custom?

[Revved]

Hey all,

I've got a client that I'm just wrapping up a high end rebuild on a 70 Chevelle. He has been using Haggerty but now that the rebuild on his car is complete he is trying to up his policy and they won't insure anything over 700hp for street use.
He tried the "show car" approach but we are going to be driving it 1500 miles back to where he lives here in a few weeks so they wouldn't bite.

Who else handles high end customs?

Thanks!