I have a tuff stuff mini starter on a street rod with a 350 chev motor half the time the starter doesnt turn the motor over it engages but dosent make contact with the fly wheel, then two tries later it will start normal ?

The starter needs to be able to drive the gear on the bendix out to the flywheel or as you said, it won't work. Generally the solenoid does that by way of a lever. I'd remove the starter and check to see what's causing it to bind up. I've built lots of high horsepower engines and unless there's a huge clearance problem I use a normal factory starter (old style) on just about everything. On very high compression engines I make an ignition cut out so you can get the engine spinning without spark and then turn on the ignition.
If you can see the gear not engaging then it's not being driven out far enough. If you can't see it, then suspect the bendix itself as well.. It's an overrunning clutch and if that's bad it will engage but fail to turn the flywheel.