Geeze, Pat!!
If I would have known..........
Anyway......since there is so much revised educated opinions on the big blocks, I guess....the only thing I can suggest now is............put the running 400 in the car while you rebuild the 413, and that will let you experience how the 400 will run until the 413 is done.......and when you re-install that motor stock, rebuilt------let us all know the comparison!!!
Please keep us Imperialist people imformed!! And a Very Merry Christmas!
Chris 60 Crown