You might want to use 3" to 4" long pieces 1/2" NPT solid pipe coming straight out of the block (steel or brass or stainless steel). Or, use bendable 1/2" tube with fittings (as shown at the link below). GM used bent metal tubes, presumably to clear exhaust system parts.

http://chevy.oldcarmanualproject.com/shop/1959trucksup/59ctsms0803.html