Olds 455 Rocket into a \'79 K10? Looks like I'm trading my way into a healthy 455 Olds Rocket motor and thinking about using it in my '79 K10/20 to replace the tired 350. I know there are some adapter plates available cheap for the bellhousing bolt pattern but what about the flywheel? Are they internally or externally balanced on the 455? Anyone know about motor mounts?