Yes I do believe the only difference between our engines is that mine is a 2 piece head, that is you take the cam out from the top not the side. It seems to be of good quality, doesn't get too hot and the throttle response is awsome and idle is smooth. I have noticed a little more vibration but thats to expect from a large single compared to my old 100. I can ride on one all day in second gear. Overall the fun factor has gone way up. If you need any help wiring the ignition let me know, I made my harness from scratch.
I just installed a very similar engine in my 71 sl100 frame. It definately had larger mounting holes. I used the existing mounting bolts by using telescoping copper tubing, the tubing that comes in 1' sections usually found in your local hardware store. About your front mount i'm not really sure how to modify that as I am not that familiar with your frame. If you have a welder you could posibly cut and extend the tabs. Here is a picture of my engine for a preliminary test. By the way, this Lifan pulls the hell out of a 190 pound frame.