FS9 Aircraft conversion to FS8

Hello! I have Paul Clawson's Howard DGA-15 for FS9, and would like to use it in FS8. The a/c comes up in the sim, but here's my question:The RPM for the a/c stays at idle. When I try to increase or decrease throttle the a/c stays at idle. I think the problem lies in the .air file. Is there a way to modify the file so I can get the throttle to work? I checked the throttle on my joystick with other a/c and it works, so I know it's not that.Any suggestions?Thanks for looking, and for everyone's help & assistance.Alan :(