Because of the higher compression head, 1956 thru 1962 are great engines. The very best for less maintenance if you are not into doing valve adjustments, etc is to go with Hydraulic Lifters. If it's not Hydraulic it shouldn't be a show stopper. These engines usually come in cars of the era. The water pump location can be adapted using one of our Bolters special Adapter plates.
There is no way to tell what the one you are looking at is for sure until you do some research. Write down the 7 digit number starting with 37 or 38 just to the left of the road draft tube and under the Distributor. Also write down the numbers on the flat area to the left of the Distributor. Then, write down the exposed number on the Head again a 7 digit number. Once you have them, tell us here and we can help you with the exact information you seek.
Lastly, you want to make sure it hasn't been bored out so many times it cannot be rebuilt. Get as much information out of the owner as possible.