'64 Dodge: subbing a Slant Six for a tired poly 318

[firedome]

Putting together a '64 Dodge 4 dr as a daily driver, which means, looking forward a few years, good gas mileage is important, and already have other big engine Mopars anyhow... so am considering possibly replacing the tired orig 318 with a /6. What's involved? given it has push buttons would it be best to stick with a '64 or older Slant 6? any other considerations?

 

[Montclaire]

You could just buy my poly that you have been asking about. It was running/driving fine last year when I pulled it, and it's been stored inside ever since...