Bonneville pre-entry form vehicle codes

[Ironwigwam2@aol.com]

List or Dan ,
   I am filling out the entry form for our first time out to the  salt this 
year and I have a question about the code. Now I know we are running a  750 cc 
flathead streamliner motorcycle and I found the code for streamliner in  the 
2005 rule book, 451.
   The flat head engine gets a 50% displacement advantage, so my  question is 
the engine code for 750 cc or is it for two engine sizes less, 500  cc for 
the advantage factor.
   Thanks in advance.
   Rick