I have a 98 blazer, with the vortec 4.3, what is the stock size of our throttle bodies? and has anyone ever tried one of these?

Throttle Blade w/o deflector - eBay.com


*EDIT by swartlkk* - condensed long link

 

Rip off!

You can do this yourself in your garage if you'd like... I did it on my old Bravada and regretted it from day 1. It makes the throttle quite jumpy and didn't improve my times as evident in my before and after scans with my scanner.

 

So throttle body modification will not benefit these motors? I would imagine that streamlining the airflow into the motor would at least inprove efficiency?

 

Well, the problem with all out hacking the deflector off is that you dump all of the air at the front of the intake. With the intake configuration on the 4.3L v6, the throttle body is located at hte absolute front of the plenum.

This throttle body is the exact same throttle body used on the 5.7L Vortec v8 with the exception that it has a 3/8" tall deflector. The 5.7L TB is located closer to the center, but still not centered on the intake.

The function of the deflector is to promote a more even distribution of EGR gases which are drawn into the intake through a pipe in the very front of the plenum. Now what most will say is 'screw the EGR, I'm just going to block it off' and I'd say have fun with the detonation afterwords. But that's a topic for another thread.

So if you were going to do anything, remove the blade from your current TB and cut it down from 5/8" tall to 3/8" tall.

 

AH! I understand that... I am used to 305's and 350's with a carb setting directly in the middle of the intake manifold. thanks

 

I did this mod and love it. I have a 2001 ZR2 and I think they phased out the EGR. It makes lower rpm's and shifts better. I wished I had done it a long time ago.

I too had the sticky 'jump' throttle afterwards, but it was the throttle plate sticking to the intake. They get used to being in one spot over 100k miles, so when you remove it to cut it doesn't go in exactly the same. I put some bolt juice on it (the stuff that frees loose nuts) and it loosened right up.

I think it was the best ten minutes of mod I've done yet.