Ok I have a 1987 I-ROC im putting in a 1996 LT-1 will i have to change my fuel pump.

 

If you had a TPI engine beforehand and dont plan on too many upgrade, the old pump will be fine

If you had a carb, V6, or TBI engine, the pump has to be replaced

 

Absolutely need the fuel injection style fuel setup that has the fuel pump that goes inside the fuel tank that was found on MPFI V6, TBI and TPI. It's hard telling what condition and kind of pump is in a 20 year old car that may have had multiple owners. If the car was carb then may also have swap out the entire fuel hardlines with ones from a junkyard fuel-injected thirdgen. If an in-tank fuel pump is questionable after the LT1 is installed then a fuel pressure gauge should be hooked up to the LT1 fuel rail to verify the correct fuel pressure. It would be a good idea to replace the fuel filter and then check fuel pressure anyway. Also, could connect the complete LT1 fuel rails to the fuel lines, prime the pump, and then check fuel pressure before starting the engine.