Yes you have the PK-80 engine that I think is a better build engine as far as fit and finish than some of the others, the longer clutch arm is for better leverage an alignment with the cable as it come from under the carb.....
The silver paint is something I like about the X80A, it gives it a good uniform finish and makes it look as though it has had a bit more attention to detail than a raw Chinalum finish.
One thing you will find is that the Muffler on that engine is very quite and could be more restrictive than you like, but a friend of mine who also has that same engine is getting around 34MPH with 72:1 Opti 2 and a 44T sprocket and just a moderately tuned carb and NO other mods and his runs nice and smooth too, I've rode the bike and it is a very sweet riding bike with that engine on it.
I hope you have the same results as he has, if so you will be very happy with that engine, I have a brand new lower of that engine I plan to build up real nice for a shifter bike.
Best wishes with the new BGF engine, break it in right and have some fun.
Peace