diesel question about an '87 Burb

[72timemachine]

I am interested in this 87 Burb that has the 6.2 liter diesel engine, the guy selling it say there maybe either a blown head gasket or a problem in the heads.

The owner of the Burb is out of town, my question is. if the engine blew a gasket or has some head trouble does this mean I should not fix it because I would be better off replacing the engine?

I know the compression ratio in a diesel is crazy high compared to a gas engine so that is why I am thinking there could be some big time damage.

I want to keep the Burb a diesel.

Thanks ahead of time for any help.