Engine swap?

Mates got FXR 180 gilera engine he wrote his ped off said can have it for 150£ will it fit in my Aprilia sr125? 1999 2t

 

If the engine still runs, have it, clean it so it sparkles, flog it, easy £350.

 

Yes runs and rides fine his frame bent and all his plastics does me for will it fit in mine? Both have the drum rear

 

Measure the engine mount distance, also cylinder head/barrel length for clearance through the frame, silent block positions, shock absorber position, and all that.