the differences are that the OBD2 blocks have Crank sensors on the oil pump housing.

If you get a OBD1 block, and your going to keep your car OBD2 then you need to put an OBD2 oil pump on the OBD1 block.

if you are converting to OBD1, you dont need to swap the pump out.

Do you even know where the fuel pump is in your car LOL