Pilot bushing for 4 speed swap

Did you grab the flywheel and all that, too? That gets expensive fast. Your engine should be neutral balanced as should the 340. (except late 340s with cast cranks). Which ever way you go, whichever pilot bushing/input shaft combo you end up with, test fit it without a clutchplate or pressure plate. Make sure your input shaft doesn't bind or you will forever be chasing problems.