Good night friend Salvatore2008. The Vistec 4.3L engine of the Chevrolet Blazer 95 uses a sequential injector (they call it a spider because of the form it has) with a regulator incorporated as a whole, located inside the bacion camera that covers the Camarin to be able to change it you must disassemble that lid or bacion camera, and then disassemble the set of regulator. You must be careful when taking out the injection extensor peaks that go to each cylinder because due to the time and heat that supports the plastic of the tweezers that fixes them to each hole this plastic is split. Greetings and I hope it is useful. We are in Coro - Falcon - Venezuela.