two ways to go:

Put a "stock and running" engine in it with the same block, so you can drive until you get time to pull your current head and put it on
the same kind of block that you had.....then everything
will be back to where it was.....Advantage, gets you back on the road now while you build something. Requires that you buy: 1.a running engine for now, and 2.a block to put your head onto while you can have use of the car..

OR

If you have time, build something now. Take the head off your busted block and put it on a good block, and put that back in the car......disadvantage, the car cannot be used immediately as if you
had taken option 1 above.

Advantage, you don't have to buy a "stock and running" engine.-Bob