what's better? the 1g 4g63 or the 2g 4g63? i heard that the 2g ones are more vulnerable to "crank-walk", what's that?  

me personally i like the 1st gen (6 bolt) over the 2nd gen (7 bolt) entirely for the crankwalk issue.  Crankwalk is when the crank "walks" or slides to the left or right, and the counter weights start to collide with objects on the block.  Honestly, i had never even heard of it before wrenching with my buddy on his 1st gen talon. altho i was born and raised in a "drive a v8 or we disown you" family, so ive just started my tuner phase of my life lol  

the 6-bolt fits into the 2g eclipse without fabrication?  

im 98% percent certain. I know it bolts right into the motor mounts, but youll at least need the flywheel and clutch pack for a 6 bolt (as you cant take a 7 bolt and bolt it to a 6 bolt, holes wont line up obviously) but im not sure about if the trans will bolt right up, and my buddy (who is my dsm guru) is unavailable. I do know its a very common thing to do with the 2nd gen eclipses, but im 98% positve no fab is involved. Check out a DSM forum, or once my buds outta work ill consult him and let you know  

thanks  

both gens have horrible problems with burnin oil. if your gonna spend the money then get a 4g64. more power more torque.