I'm sure by now you know that an export is not a true backup. Going forward you should look into using RMAN, provided that you upgrade to a supported version. Such as 11gR2. In order to do the restore you need a new database, it is ok if you use an 8K block size rather than the 4k block size that you used before. You need to make sure that the schema's and tablespaces exist before you do the import. If the directory where you are putting the data files is different it helps to have the tablespaces created ahead of time. Creating the users/schema's ahead of time allow you to more carefully specify default tablespace and temporary tablespace. It will also help to have the listener configured and running ahead of time.

When you do the import you want to specify most of the following:

imp system/@ file= log= fromuser=,,etc touser=,,etc buffer=102400000 ignore=y commit=n statistics=none

You may need to treak the above command and everything in <> needs to be values that you supply. You really only need to specify the buffer command if you use clob, blob, long, long raw or raw. it doesn't hurt to add it if you aren't sure. Ignore=y tells the import that it is ok if things already exist. Statistics=none might prevent you from getting warning messages about having bad statistics. commit=n means that it doesn't incrementally commit while it is importing. It is better to specify individual schemas, rather than doing full=y. Because when you do full=y you will get data dictionary information, which you don't want.

Good luck and if you get errors post the log file.