Alum Heads

I don't if that is exactly true but if so, probably 340/360 comes with decent heads so depends how much power your looking for, stock especially with a little work can make pretty good power. 318 heads are good for about 300 hp so if you want more then that could go 340/360 head but there's the compression problem then if start putting an good amount of money into them might as well go with new heads, 318/340/360 all can benefit from a good set of aluminum heads.