440 or 400???

All we did on the boys Dart pictured here was put front disc from a 74 Dart. No power just disc. Still has the stock 318 torsion bars and suspension. Been like that since 1997 with no problems. I figured it was a 318 ac car and we removed the ac along with using headers and the aluminum intake I figured it really did not add much weight but maybe 100 lbs or so when going with the 400. Ron