Whats the deal w/ thing being for 87-89 TBI units only?? Did they change the TB at all in 90? I want to try to get the most out of my TBI 350 in my 90 Sierra and the Holley TB was part of it.

-Timbo-

 

1988 on had two injectors instead of one, but i dont think they changed anything. Of course my TB history is a little vague.
~Tim

 

The Holley TB flows a lot better than the stock GM right? So would it would work on the 90-95 V8s as well?

-Timbo-

 

All TBI was 2 injectors unless you're talking about something other than a v8, if that's the case go check out the v6 board. TBI was found on crossfire setups way back when and that setup used 2 single barrel setups but with massive injectors (67#).
My dad's 87 suburban used the same 1 and 11/16" bore with 2 injectors as my 91 and his new truck, a 95 burban.
They all swap on and they all work. It's the larger 2" version that you need to make sure will fit your intake manifold (most likely not). You would need either a carb intake with an adaptor plate or a holley specific TBI 2" bore intake manifold.
As for the free slowing, holley isn't any better than a worked over GM unit. It's really easy to make the GM unit flow just as well. All you need to do is mill off the ridge runners on the top of the bore and maybe install a thicker injector pod spacer.

 

I agree with JP and I might add to make your fuel pressure regulator adjustable.

For those that haven't been there the tech section has some good TBI projects. IE: the unltimate TBI. Parts one and two and an article on the AFPR.

Good luck!