You probably still have the stock TBI tank in your truck. The tank is externally the same, but fuel injected trucks had a baffle inside so sloshing fuel won't cause the pump to suck air. Carburetors don't care about momentary air bubbles in the fuel line, but there's no downside to running a baffled tank. You probably have a different fuel pump with a lower pressure rating, but some folks just put pressure regulators on the stock pump. Something to keep in mind if you want to replace the pump. Assuming the pump is still inside your tank, it's a good idea to write down the part number before putting the system back together. Just so you don't wind up buying the wrong pump later down the line.