Sorry this isn't F-body related but I tried to post this in the form that it would relate to.
I am currently building an engine for my 94 full size Blazer. I am unsure about what size throttle body to get. Here are the engine specs

5.7 boared .040 over
Speed-Pro flat top pistons
LT-1 cam
Vortec Heads - 1.94/1.50 64cc
Gm Performance Parts intake - intake specs.
Shorty Headers
Cold air intake

Here are the ideas I have had for TBs What is your opinion?

Stock 5.7 with flow matched injectors and a AFPR

Stock 5.7 with flow matched big block injectors and a AFPR

Stock housing boared out like this one -click here

Big block Throttle Body

I will also be getting a custom Prom chip once I have this all done.

Thanks

 

Made a error in thinking it was a TPI...

 

Because this is a full size Blazer, we are talking about TBI, not TPI.

You will want all the flow you can get, and then match the injectors later. That EBay piece sure looks nice, and would compliment the airflow needs of your engine well. An alternative would be Holley's direct replacement unit. Although it is a direct replacement, it flows better than a stock piece. Click here for more info.

I am not sure about the differences in the late 80's TBI which I am familiar with, and your 94 setup. They should be similar.