Lol... I'm so confused with the 4.3L. I just want to know exactly what kind of fuel injection system I have on my motor. It's a 1997 Blazer LT. I keep hearing SPI, EFI, SPIDER, etc.... what does this truck have? I hear a "spider injector" can be an upgrade or something? I already have a cold air intake, throttle body spacer and full exhaust. I'm working on getting an MSD Ignition and performance plug wires next, shortly followed by a PCM tune. Then I'm done, don't need anything else. MAYBE Headers one day, maybe. Once this motor is done, ill drop a 350 in it and keep going. But that'll be YEARS from now.

Back on subject though.... can someone tell me what type of fuel injection system I have so I can know of there's an upgrade for it.... thanks a lot!

 

EFI=Electronic fuel injection. Generic term for all fuel injection.
Spider=nickname for the fuel injectors. It looks like a big black spider with 6 legs.

You have an SCFI injection system, the upgrade is the MFI system from a newer Blazer or Jimmy, according to wikipedia.

Chevrolet S-10 Blazer - Wikipedia, the free encyclopedia

Second generation engines

1995 - 4.3 L (262 cu in)Vortec 4300 L35 V6, CPFI, 195 hp (145 kW)/250 lb·ft (339 N·m) (VIN W)[5]

1996–2002 - 4.3 L (262 cu in) Vortec 4300 L35 V6, SCFI, 190 hp (142 kW)/250 lb·ft (339 N·m) (VIN W)[6]

2002–2005 - 4.3 L (262 cu in) Vortec 4300 LU3 V6, MPFI, 190 hp (142 kW)/250 lb·ft (339 N·m) (VIN W)[7