273 same as a 318

Hi Guys New to mopars.My son has a 66 cuda with a 273.I was woundering if a eary 318 motor will drop right in with no problem.Thanks Randy

If by pre 68 318......no

After 67...................yes.

I changed a /6 barracuda over to a 273 with no problem, however, I first tried to put a bb 318 in from a wrecked 66 Plymouth Fury and had to rethink the engine transplant and go back to the 273... Good luck...