HP-UX v11 in 64 Bit mode compatible with IDS v7.31.uc2?

I am trying to set up a test system to evaluate the impact of moving my corporate database from an older Sun box to a new HP 9000 Unix server. The new server would be running HP-UX v.11, which runs in 64 bit mode on all of their new servers. I have just found out that my test server, which is an older unit, does not support 64 bit mode. I talked to HP and they advised me to set up the test system with HP-UX v.11 running in 32 bit mode. According to them, anything that runs on HP-UX v.11 in 32 bit mode will run in 64 bit in "narrow" mode. I am not satisfied with their answer. I have a limited time to test and I thought I had the perfect environment to simulate the OS that I was migrating to. Now I have to take their word that I can go from 32 bit to 64 bit later. Does anyone out there have any first hand knowledge of running IDS v.7.31.uc2 on HP-UX v.11 in 64 bit mode? I will also be porting some 4GL and IQ scripts as well. Any help would be appreciated. -Craig