Only thing I could see being a problem would be subtle differences between the 4th & 5th gen engine bays; which may affect anything hanging off the motor. Which gen header will you need? Will the 5th gen IM rub the firewall? But the major elements 'should' be ok: tranny, block, head. Just my 1st impression. Like you said, it's slow... hope that helps, but you've probably thought aboot all that already.