So you want 2 go Big block...Read this first!

I'll get pictures of mine.
My '71 Dart uses the stock /6 front end.
And my '72 Demon uses the stock 340 front suspension.
Unless someone changed your front end to a '67 Dart, I can't understand why it wouldn't fit.
What mounts did you use?
I used a B body Oil pan. and Schumaker mounts.