I picked up a 98 civic ex with a jdm b16 and a b16 tranny not too long ago, and when i shift hard in high revs it grinds really bad in 2nd and 3rd. Its a long grind, sounds like im not pushing in the clutch when i shift. Then sometimes it doesnt grind at all. I dunno if its my syncros or if i should drain the tranny and put some syncro mesh in it? Or could it be my clutch pedal not adjusted right because it seems a little loose too me.

 

You should first make sure the correct fluid level is indeed in the transmission before anything. Make sure it isn't over- or under-filled with the correct fluid. Once you have that addressed, make sure the clutch pedal is indeed adjusted correctly. If it's still grinding after both of these, then chances are that those gear's synchronizers are damaged/worn and will need replaced. It's common.