My version of a factory parts build 318

Also, FWIW, the 915 is a 340/360 head. They cam with ether a 1.88 or 2.02 valve but both had 1.60 exhaust valves. These can be made to perform very well. But you’ll have to weigh the cost vs aluminum heads and check to see if it aligned with your goal and build plans.

If racing, does the class allow aluminum heads? (Probably so!)
If not, and you must use cast iron heads, are W2’s allowed?
They are a very good cylinder head.