It sure helps to see actual good bike pics for help but...
Let's start with basics...
1. Your back engine mount has to be dead tight to the seat post at a true 90 degree angle. That is the 'stop point' for power transfer to the bike frame with it's full surface and NOTHING in between, metal to metal.
If the stock block piece does not make the engine level make a new one.
2. Once the back will hold your engine in place all on it's own, fab in a front mount to keep the engine from moving left from the drive torque.
That's all it has to do and you make that with whatever fits to work.
3. Getting a broken stud out is tough.
The engine casting gives way more than the stud and it's easy to screw up.
I've have had to do this a couple times and I have found a combination of the right ~1" Dremmel type thin cutting wheel and making perfect X into the stud end, drilling a little pilot hole on end of that, and putting in a reverse thread EasyOut bit will get the broken stud out without and damage to the case.
I recommend going with the SBP mount, it has all kinds of spacers, can be mounted in various ways, and work great.
http://www.sickbikeparts.com/catalo...ducts_id=74&osCsid=c9tm401cnfkr2kt4eq004u0nv6
Again, it all starts with the engine true to the seat post and then get the front to hold it from twisting and the SBP bracket is nice but you can make your own...
Start with a muffler clamp that fits your front tube and gives you a flat spot to mount to, and then put something in between for the front mount.
Examples of extreme front mounts that do the job just fine.
Hope that helps.
http://motorbicycling.com//www.pinterest.com/pin/create/extension/