Need little help 340/4sps 70' Dart Swinger

if it is an H VIN code, I'm thinking 15-20 grand. Put it back to original, and I have seen asking prices of 40 grand.
Non H code cars go for 15 K in my area of the Northeast, that is a 'Clone" 340 Swinger, and sometimes they don't have the 340 in them, its usually a 360.