einheit13 yuor ultimak on bulgy holds in 3 spots.
1- gas block
2- rear sight block leaver
3- 2 bolts on the middle.
With Yugo gas block beeing good 1/2in - 3/4in further, and rear sight block leaver is not holding it either there will be only bolts on the middle holding it.
There will be problems like: gas tube will be off to the bottom therefor it will not provide a good guide for the gas piston. Especially after you shoot it, from the recoil it might move to the side, because it is beeing held only on the middle (not in the rear by the leaver, and not in the front by the gas block).
Now even if you are right and from shooting it will expand, metal doesn't expand 1/2in to the front. Now You might be still good because it is just little short, but with having 1/2 gap it might be a problem.
Also it might of been alright if the rear leaver would be holding it, but without it, the mount will not have sufficiant tightness.
You wanna try it on a Yugo, go ahead, but it will be a weist of time and money.