I'm thinking about using a throttle body fuel injection on my 394. Any ideas?

 

Save your money, and buy whiskey!

Seriously, getting an EFI system to work with a "Slim Jim " transmission would be a challenge to a skilled engineer.
And if you get it wrong, you will burn "ol' Jim" up,
There may be some fuel savings. but considering the cost of the EFI installation, how many miles would it take you to get that money back in fuel savings?

The stock Rochester 4GC four barrel flows 700 CFM .
If you want to improve power, consider a higher lift and longer duration camshaft.
And dual exhaust if you don't' have it.

 

^^^THIS^^^

If you're going to spend that kind of money you should invest in a replacement for that Slim Jim Rotohydramatic you have.

 

Thanks