AMC 401 engine for my 1972 Duster

I will just add to what a lot of other people have said. Sell the 401 and find a Mopar small block. Even in Costa Rica there has to be a 318 or 360 laying around somewhere. You will have problem after problem after problem getting everything to fit and work well together. Is the 401 a good engine? Yes, but that doesn't mean it's a good idea to try and stuff it in. Way too much trouble. Also, unless you are an excellent fabricator, whoever overcomes the problems of mounting everything and getting stuff to fit is going to want some money. Find a small block Mopar. I bet it will be way cheaper in the long run; not to mention a LOT easier.