The C-4's are not that expensive to rebuild and will handle all the power a 289 can put out when built properly....

Windsor heads are interchangeable, just watch your cc's on the head. The old 289's were a small chamber head, going to a head with too big of a combustion chamber will kill the compression and as a result, the performance of the engine. With the right pistons, most any head can be used to build the engine to a good compression ratio, around 9 or 9.5:1. If you would choose to use aluminum heads, then you can get away with about 10:1 compression ratio....