Sure you can! It's one of the major functions of BBSAK. You can sideload any app that you have the CODs for.
Originally Posted by californiablackberry
Unfortunately for the OP, App World will only let you download CODs for your specific device. If a website doesn't support the 9810, often you can get 9800 CODs by just telling the site you have a 9800. I did this with Garmin Mobile a while back. You can probably do this at the CrackBerry App Store as well.
Some 9800 CODs work perfectly fine when sideloaded on the 9810 (e.g. EveryHour). Others have superficial screen issues because they were written for a smaller screen (e.g. ParkMobile, GarminMobile). Others don't seem to work at all on the 9810 (I'm looking at you, Morningstar).
One annoying thing about side loading is that App Loader almost never recognizes sideloaded apps, so I end up side-loading a dozen or so apps after every OS update. This can be remedied by writing a .ALX file for each side-loaded app by hand. But it's easier for me to just select all the CODs I want to load in BBSAK.