413 swap

The 413 used in Motor Homes is a 413-3 HD truck engine. The cylinder heads are unique on this engine and require special exhaust manifolds that will not clear any passenger car K-member. These heads will not accept any other manifold or header, the exhaust bolt pattern is different to any passenger car or later truck or motor home (440) engine. The water pump and housing are also different (6 bolt pump with greasable bearing). The short block should be usable, but these engines had lower compression than passenger car 413's, also check the crank flange, some of them are 8 bolt. The 727 trans is likely to be a short version with a bolt on flange, not a slip yoke.

Whether you choose to use this engine or not is up to you, just be aware that it's not easy.