finally it looks like V-8 time

I would chuck the TBI setup. they do not do any better as far as mpg and as far as reliability you have more things that can go wrong. the system relies on all the sensors and unless you buy all new stuff you still have a bunch of outdated, used equipment. If you want to go FI get a newer multi setup that would get better mpg and is up to date technology. for easy setup and to keep it simple go carb.