Postgres upgrade and converting latin1 to utf8
Here are the steps you should perform:


Dump roles and tablespaces with pg_dumpall and the --globals-only option 
Dump data and schemas with pg_dump and the --encoding option to have data in utf8 for each database
Create each new database on new server with correct encoding  
Restore roles and tablespaces on new server
Restore schemas and data for each new database


Here you will find documentation for pg_dump and pg_dumpall in 8.1:
https://www.postgresql.org/docs/8.1/static/app-pgdump.html
https://www.postgresql.org/docs/8.1/static/app-pg-dumpall.html

And here you will find documentation for pg_restore and psql (your restore tool depends on your dump options) in 9.4:
https://www.postgresql.org/docs/9.4/static/app-pgrestore.html
https://www.postgresql.org/docs/9.4/static/app-psql.html

And here is generic documentation about databases encoding in PostgreSQL:
https://www.postgresql.org/docs/9.4/static/multibyte.html

Have a nice day!

Arkhena