Have 70 Challenger, 383 Magnum.

I guess these are the 906 heads.

Previous owner had rebuilt the engine , not sure what was done to heads.

A few years later, I think I have a blown head gasket.
I would have a shop do all the work, I am not physically able to do it.

If they remove one head, I assume both should be done.
Also, perhaps the valve seats need upgraded?
And what about a 3 angle valve job for more power.

I had one shop tell me on the phone about 2 grand just for two gaskets.

Ballpark figure and advice to be done.

Thanks