Does the front sight assembly have the enlarged muzzle area for the 24mm brake and it's not threaded, or is just the actual barrel itself exposed?
If the front sight assembly simply isn't threaded, it's possible to thread it, but I don't know if anyone sells the correct threading die and Thread Alignment Tool or TAT.
The TAT is a stud that screws into a threading die and is a slip fit into the bore. This aligns the threading die and insures the threads are square with the bore. Threading without the TAT is only something you want to try in a lathe, and that requires removing the barrel from the receiver.
At that point, you're getting into a really major job.
If the actual barrel is exposed, you could probably use an AK left hand thread threading kit to thread the muzzle and then you could screw on any standard 14mm-1.0 Left Hand threaded AK muzzle attachment.
This presents some problems with finding ways to lock the attachment in place so it's won't unscrew.
If you want to install the correct AK-74 front sight assembly that has the 24mm Right Hand threads to accept the AK-74 type muzzle brake, unless you have access to a heavy duty shop press and some knowledge of how it's done, you'd be better off having it done.
One issue of this is determining if the available AK-74 front sight assemblies will fit your barrel.
Barrels and sight assemblies do vary and you have to have a match.
In order to do this you use a heavy duty shop press to press the old sight assembly off, after driving out the pins.
A new assembly is pressed on and new pin holes have to be precision drilled.
My suggestion, see a good gunsmith and between the two of you figure out your options.
