I've been doing a bit of research online and the engines of both seem to even each other out.
I'm not a mechanic, so I cannot say which one is better,..........
I am going to be Brutally honest with you.,,,,
I really DO NOT CARE how much or how many hours you spent researching about American made vans and engines.Even if you can decied on what drive line to use.Being located where you are will have a major out come on what it would cost you to build ANY type of project.Not have mechanical experience and having to depend on a paid wrench can really complicate things more than likely for the worse, money wise the out come of any of your proposed projects.
Sorry it is almost senseless trying to explane wich engine combo is better just for the simple fact that you just don't have the access to the wide variety of American made engines that we have over here......
Reading you posts you have went from building an A Team clone to a VW van with V8 power........WTF?????
The one fact I will let you in on is Street Rodders use Chevy drive lines for one real reason INTERCHANGEABILITY.
For example
Unlike Fords engines and transmissions.Chevy's can be swapped out from the inline 6 to the V6 to the small block to the big block the bolt pattern on all of the Chevy engines are the same.
There is a boat load of other parts will interchange, staying with the same type of block
.......Wookee