David,
When you take delivery would you post the frame # and the engine #.
We can get the year from those 2 things. It may take a 175 cc top end if its a 79 i believe.
I have access to some books that will let me know once i know the engine #.
Its an option you could go to at a later date if you wanted a bit more torque.
I have a 76-79 175 6 fin KTM cylinder grafted on my Sachs 125 A engine.
Makes a very light engine ( 20 LBS lighter than a KTM engine ) with a good bit of torque for a small bore. Easy to ride for old fat enduro riders like me chuckle chuckle!!!!!
john d.