I know there are a ton of posts on vibrations, but everyones are different so I didnt feel like searching.

I have 2:

1. In neutral when I rev it there is a slight vibration at higher RPMs, I replaced the flywheel so it better not be that. Im guessing either motor mounts or a bolt came off the pressure plate.

2. When im cruising at about 90 then put the clutch in the car shakes pretty bad, but when I put it in gear it goes away. My guess there is the driveshaft, Im almost certain thats where that one is coming from, I know these two vibrations arent linked so I have two problems.

Another question, if I replace the motor mounts with solid steel ones how do those feel, does the car shake a lot worse or what. What would you suggest getting?

 

First, if you put a solid motor mount in, it will shake the hell out of the car. I chained an engine down with a broken motor mount and it rattled everything in the car.
Did you transfer the balance weights on the flywheel?
Your vibration at 90 may be u-joints. Your prop balance should be ok otherwise it would vib. clutch in or out. Props. don't vib. because of load, only because of RPM or driveline angle problems.
Try indexing the prop 180 deg.
Did the vib. start after you replaced the flywheel or did you replace the flywheel because of the vib.?

 

Im not sure if im just really tired, or just dont know what the "props" you are talking about are? But explain that again for me please. And I replaced the clutch, before that the flywheel was fine, after the clutch came a horrible vibration where I couldnt take it above 3000rpm (the machinist F'd it up resurfacing it), so i replaced it with the SLP billet, which is zero balanced. The vibration is very very light, but at one certain point it resonates with everything in the car and it shakes. I dont know if any kind of mounts could cause this but im always shifting pretty hard on a daily basis so the tranny mount could very well be shot, if that helps. Im not really worried about the high speed vibration because as long as i keep load on it its smooth all the way to 15?mph, id still like to pinpoint it for the future though. Hopefully that will help get me more help cuz I would like to get rid of the other vibration.

 

If you go with solid mounts your vibration will increase 10 fold. I have solids in my ride. but very little vibration mostly at idle. not too annoying but my wife hates it.