Price Motorsport sells all kind of adapters for nearly every block- intake and head combination you can think of (
www.pricemotorsport.com).
The part number for Windsor block with Cleveland heads and a 351 windsor intake is AP-16, if you want to use a Cleveland intake and 351C 4V heads on a 351W block you need adapter # AP 15.
They also sell an adapter to install CLeveland 2V heads on a 302.