Aluminum Slant

Ok so it was warm today and I went to local pisk and pull to look around.I found a 62 Valiant with aluminum / 6 and push button auto .My question is what is it worth,should I buy it and build it for my 69 Dart,or put it back for a rainy day.I can get both engine & trans for about 250.00 and no it doesnt run but turns over by hand.What size would it be.