Thinking of changing my bottom end in my spec sheet i got for the car.. Im gonna go with a CVH Big Valve head (do RS1600i Engines have big valve heads?), cam to suit, twin 40 downdraft carbs, four branch manifold etc. I was gonna go with 1.8CVH but ive heard of these "ZVH's" now and im interested.. How much work is it to fit a 1.8 Zetec bottom end into my XR2 MK2 and what kind of work is needed? Any help is appreciated! Cheers