from "Flavors of Cape Cod" recipe book:-
3 cups shucked clams
1/4 pound salt pork, diced
3 medium potatoes, pared, diced
1/2 cup onions, chopped
1 cup water
2 cups milk
1 cup light cream
2 Tblsp. flour(optional)
1 tsp. salt
1/2 tsp. pepper
2 Tblsp. butter (optional)

Drain clams, reserving liquid. Add reserved liquid to water and boil potatoes
until just barely soft. In frying pan, fry salt pork until crisp. Remove pork
bits, add potatoes and onions to the pan and saute until onions are soft. Add
clams, milk, cream and seasonings and heat until just below boiling. If you
like a thicker chowder, mix flour with a little water and add, stirring until
slightly thickened. At serving time, a small amount of butter may be added to
each serving, if desired. Quahogs or little neck clams make the best New
England Chowder but canned minced clams may also be used.

How thick a clam chowder should be has inspired many a discussion on Cape Cod.
The answer is "However thick you like it"! Serving salt crackers or biscuits to
be crumbled up in the chowder seems to satisfy some "old salts" who insist that
a soup spoon must be able to stand straight up in the bowl!