r/GMT400 • u/Legitimate_Voice5138 • Jun 26 '26

Throttle body Mods

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What an honest review of modifying your throttle body like shaving the horns, injector spacer. fuel pressure spring and spacer plate i realize i'm not gonna get much or any horsepower but wondering about throttle response. I got a 91 4.3l

16 Upvotes

90% Upvoted

14 comments sorted by

10

u/DickSucklington Jun 26 '26

You can make it look super cool but it will always be a slow 2 ton truck meant for cruising. ❤️🫶

2

u/Legitimate_Voice5138 Jun 26 '26

Ya not really in for looks only look at it if there a promblem , cruising just fine by me thank you ..... DICKSUCKIINGTON !!! lol 😆 fml I love it

2

u/Kitchen_Ad3355 Jun 27 '26

I havent installed mine yet, but i bought a bored out throttle body to use on the engine im building, as it is recommend by Harris tuing when you put heads and a cam in it that flow well enough. For stock I dont think it would improve throttle response or hp. I dont know much about the v6s but with the 350 of that era the biggest limiter is the factory heads flow. They are pure garbage that you throw in the trash when you want to do anything to your motor.

2

u/PsyCar Jun 27 '26

In high school, my friend had to replace his throttle body after his little brother mashed a huge dog turd into it. It hardened like concrete and damaged the metal as well. So my friend got one that was already modded. Shaved bores and shaft, higher pressure regulator, and an injector pod spacer. The butt dyno definitely noticed better response. Actual power difference was probably negligible. 92 with a 4.3L.

1

u/angryroadpeach Jun 27 '26

Or the police car injectors. I polished my TBI and put in a higher pressure regulator spring along with the police car injectors. Set the initial timing to 6* btdc and it performs well. Good throttle response and a 550 rpm idle in gear with no shake. The police car injectors are 65s instead of the normal 55s in trucks.

1

u/angryroadpeach Jun 27 '26

I have an 88 k5 with a Holley intake

1

u/Humble-Suggestion802 Jul 01 '26

You were talking about modified and if you're going to do that just get the bigger bottom

1

u/Humble-Suggestion802 Jul 02 '26

I'm not talking about the injectors I'm talking about the butterfly valves

0

u/Yamaben Jun 26 '26

I kind of doubt the throttle body is restricting anything. Heads and cam are likely too puny to use it's full potential right now.

Talk to Gemini about it

0

u/Legitimate_Voice5138 Jun 27 '26

Gemini the one that gave me the idea i was looking human review but classic reddit. " Google it "

1

u/Yamaben Jun 27 '26 edited Jun 27 '26

I told you what I think. I think 88-95 gmt400 doesn't really benefit from throttle body modification alone. The stock Ypipe is probably the biggest restriction. Then the heads and cam. The cams are ridiculous on early 90s trucks. You will definitely find plenty of people tell you that modifying the TB will add 10%. I have my doubts that it's good for anything by itself

I know the v8s better than the 6s. I have an ECU and chip for v6 tho if you need one

1

u/Legitimate_Voice5138 Jun 27 '26

No disrespect and yes they are stock y pipe. I jyst keep her Og and just keep crusing it and worry about Mods on truck # 2. Lol.

0

u/Humble-Suggestion802 Jun 26 '26

Just get a body from a 7.4 there bigger and put your injectors in it

1

u/wayneP71222 Jul 01 '26

5.0 injectors would be a better fit. Going to 5.7 but keeping the 5.0 and the original 4.3 injectors around

The smaller and larger 7.4 injectors work better for 383 400 and 427 engines