Take the bellhousing stiffeners off your 3.0 and bolt them onto the 3.4 block. There is supposed to be a flywheel cover sandwiched between the bellhousing and bellhousing stiffeners.
I don't know if "bellhousing stiffeners" is the correct way to refer to them but I heard that once and it stuck in my head... They're just the little brackets held on by two 14mm's and bolt to the bellhousing with another two 14mm's. It makes sense if you look at it.
