I just got done going from TBI to carb...there are issues that must be addressed ..in a nutshell ..
Fuel pressure must be knocked down to 5-7 psi for your carb ....whether you run the factory electric in tank with an external regulator or run a straight old mechanical style pump its your choice ....I personally ran the old mechanical pump as I didnt want to deal with the ECU , its oil pressure switch, all the relays etc ....then you have to address the pickup in the fuel tank..if you go mechanical make sure your block is drilled for the old mechanical pump and your camshaft has a fuel pump lobe - some dont .
Distributor you need to go to an old school mechanical HEI - no biggie .
Hopefully your tranny is not electronically controlled if you go carb or you will have to address that . My 700r isnt - so that was easy .
Its not a cheap swap but I like the whole old school setup in a newer truck idea and I like that I can upgrade in the future without computer tuning, tuners, chips etc ,,,,,
As others stated above tbi is going to be cheaper, you can add a cam , but then you have to deal with the tuning.