Those 213 truck heads are peanut ports for sure (220 cc intake ports if i remember right, have a similar set), you'll have to swap them if you plan on getting decent hp numbers.
If you stick with the original crank and use longer rods you can use Keith Black hypereutectic pistons, they have 3 part numbers available i think, that's what i'll use if i go with my 427 BB.
With a 3.76" stroke that thing will rev to the moon...