ZR-2, C-4 Corvette.523.C.I.D. After you've verified "parallel", next is bore centricity, Trans input/flange bore to crankshaft Pilot bearing. Using Lakewood offset dowels, we got this to 3 Thou., up to 5 is allowed. You can see the custom Ears for bolting up the ZF-6. Together, these two operations, plus the herein shown struts in the next pic., we have a 600 Tq & HP rump-rump MkV big block in a C-4 that has the drive line smoothness of a Rolls-Royce. I'm not kidding, it's as smooth as a baby's bottom! Anyone that installs ANY engine without doing these fundamental blue printing operations is foolish because premature component failure will occur due to the fact that achieving dimensional accuracy by just bolting stuff up the way it comes out of the box, so-to-speak, is as likely as winning a lottery. . PLEASE NOTE: This install was done with ZERO mod's to frame, crossmembers, power steering locations or any other fixtures on the car. It is a true "Drop-In" Big Block install. .