Is there a stand alone computer system that a guy can add to an E40D for guys that want to switch out the stock efi system for a carb or a high performance efi system like those offered by professional products or holley that look like a carb and are easy to tune, self teaching, but don't have a hook up for the trans computer. If this isn't possible, will a C-6 almost bolt into place?

 

Yep, try here:

http://www.becontrols.com/products/electronicscat.htm

 

here's one option for a standalone e4od controller http://www.optishift.com/

 

So let me get this right. You want to get rid of the more advanced EFI for carbureted, yet still keep the computerized tranny? If you're going to downgrade the engine you might as well swap in a non-computer tranny.