Hi! Yes, you have forgotten to modify srm.conf and add the next 2 lines whereever you want:
AddType application/x-httpd-php3 .php3
AddType application/x-httpd-php3-source .phps
And, in httpd.conf if my memory doesn't fails, you have to add this line:
LoadModule php3_module path-to-php3-module
I recommend you to read the FAQ on www.php.net/
Anyway, I hope this helps. Bye