how much work dose it take to drop a 351 cleavland into a 65 mustange coup orignaly set up for a 6 cylinder

 

The Windor blocks and other small blocks with C4 trans and Hooker headers are very easy to drop in. The Cleveland is going to be a little harder. You will have to hand build motor mounts and headers is going to be another issue. Is there a reason you are going with the Cleveland motor and is it a CJ motor with 4 barrel heads? What trans and rear do you want to use?

 

Clevelands use the same mounts and bellhousing pattern as the Windsors. As for headers, since the Cleveland came in in 1970, you will find headers. This swap shouldn't be any harder than a Windsor swap. As for going from an I6 to a 351C, those details I don't konw.