351w

The Cleveland has far superior heads and they are WAY wider, limiting them to larger areas. The W motor will work well for what you want. Very similar to the Chrysler engines, there's not a lot of difference in cylinder heads, so use what you have. The 4" stroker build is popular with them too, just like the 360 Chrysler. Lots of options there, but, like the Chrysler you will quickly eclipse what the stock head is capable of, perhaps more quickly than the Chrysler. What I would do would be to build a stout, stock bore and stroke 351 and call it a day. Very respectable engines.