Sarge,
Make a small investment and buy a torque wrench. I don't trust Harbor Freight tools so I wouldn't suggest one from there but many other tool places carry them. You'll want one in inch pounds.
One of the biggest problems new builders have is broken fasteners and that can usually be traced to over tightening them.
As was said above and has been posted here many times, do not put any rubber or resilient material between the engine and the frame. Bolt it down as solid as you can.
If you have fenders keep a close watch on them. They can be dangerous, very dangerous, even when reinforced, checked and tightened. Ask me how I know
Tom
