vacumn and intake ?

im running a 521 with a stealth intake and 950 hp and ported and polished c9 heads done up by scotty with a 241/[email protected] hyd cam,it currently pulls 11" vac,if i was to switch to a victor how much would it drop from just the switch. this in my mud bogger. i have a vacumn rule i need to meet of 10".could i also switch over to a custom solid cam and get some more hp out of the motor and still meet vac req's with the victor? currently its about 10.4.1 comp thanks