The TFI is
normally a good or bad thing. The hall effects seem to have hot problems when they act up.
I have a low mile '91 460 EFI down here if you want to try to shoehorn it in.
I have the in-laws coming down to take us to lunch for Sherri's birthday tomorrow but I should be able to get free in the later afternoon. I have fuel PSI tester, compression tester, ect. I can bring up.
Does that motor use the plastic intake spacers between the heads and the intake? They can burn through and cause an internal vacuum leak.
For chasing vacuum leaks, I have used water several times. It's not as quick to show as starting fluid but you always have some around.
jim
Also, just found the last piece of the governor that went flying when the cam broke.
Maybe I shouldn't help with your car.