Carburetor to TBI upgrade

Not an answer to your question , but what kit are you going with? I am thinking of that same project and any pointers would be greatly appreciated.

appreciated.

| > > I am upgrading my 305 in an 85 GM truck to TBI. The current system has a | > > computer controlled carb and ESC ignition. Do I have to replace the | > existing distributor or can I use the one in the truck. 85 G20 chevy van

The distributor (and shaft on the small block) should be the ones that came with the block. You should expect an issue with your hydra-matic automatic transmission though, because it needs data on throttle position and vacuum pressure from the computer on the carb in order to select gears.