The minimum Solaris 8 for that machine was 7/03:
<a href="http://sunsolve.sun.com/handbook_pub/Systems/SunFireV250/SunFireV250.html " target="_blank"> http://sunsolve.sun.com/handbook_pub/Systems/SunFireV250/Sun FireV250.html</a>
You should go to sunsolve and download the 8_Recommended patch cluster.
If your V250 can boot and run without obvious issues, then it will probably have a compatible minimum release of the OE installed.
Once you have confirmed that, you should be able to update your ALOM.
Keep in mind that you cannot patch your way to a newer hardware release of the Operating Environment.You must install it from its media.
For example, if the system has Sol8 HW 7/03 installed and you apply a patch cluster from 2005, you will have a patched configuration of Solaris 8 HW 7/03, not a 2005 release of Solaris 8.
If there is a need for further guidance, you should install and run Explorer, then open a service case with Sun, directly.
In my reply I was not suggesting that you can patch your way to a later release, I meant that the minimum version supported on the system is 7/03 and therefor that is most likely the release that is installed. I know someone that tried to install various earlier releases on the V250, but the kernel crashed each time ( may have been 02 release though ). I think this subject came up on the forum also, I seem to remember a discussion on this subject in the past. For someone that is not aware of the release or how to find out what release is installed, I would recommend that the latest patch cluster and firmware be installed. Then when you go to upgrade your ALOM it will be unlikely that you will run into any further issues.